Agree with @MikeM (assuming he means “Better safe than sorry” here).
You don’t know until it’s you out of your life’s work with ongoing expenses and at the mercy of what we collectively term “the markets”. Guess wrong and you might find yourself out looking for a job on your 95th birthday.
I’’m atypical in that I have a DB pension. Wish everybody did. So with that I went 6-7 years into retirement without having to touch the IRA. If you can do that, it’s a great way to build up that nest egg. But 4% yearly? I’ve been able to take a bit more than that over the past 10-12 years and not really “ding” the balance. In fact it’s grown. But I’ve been lucky. Most years I pull 5-7% out. But a couple years, for new car purchases, it’s been a bit higher than 7%.
I doubt the linked OP article even addresses the traditional vs Roth issue. If you’re pulling $$ from a Roth IRA, it’s quite likely that $10 withdrawn from that Roth will buy you as much as $12-$15 pulled from a traditional IRA would (after taxes are accounted for). So, with a Roth, you need to pull out a significantly smaller percentage to maintain the same lifestyle.
The markets are a real wild card. I’d be loath to try and draw too many conclusions from the past 10 or even 20 years. That’s too short of time. History has a much longer memory. Final comment - It seems as if the bond market is hooked on “downers” today while the equity markets are doing steroids. One wonders how long that dichotomy can persist.

FYI: Elizabeth Shaw and Charlie Holloway were digging around in a Scottish cave. They discovered a special map that, they hoped, held the key to the origin of life on Earth. It was one of the earliest scenes in the science fiction thriller, Prometheus. And their discovery was a bit like the 4 percent rule.
OK, I might be stretching things a bit. But who’s to say William Bengen didn’t discover the 4 percent rule in a man-cave of his own? Bengen, a financial planner from MIT, published his discovery in a 1994 publication of the Journal of Financial Planning. He tested several portfolio models back to 1926. His research showed that if retirees had diversified portfolios comprising at least 50 percent in stocks, they could have withdrawn an inflation-adjusted 4 percent per year and not run out of money over a 30-year retirement.
Regards,
Ted
https://assetbuilder.com/knowledge-center/articles/how-retirees-can-withdraw-more-than-4-percent-per-year

Psychologically, what helps me (in these uncertain times) is having already set up my multi year "withdrawal" bucket for retirement. The rest of the portfolio I let ride in a balanced portfolio and don't worry about trying to time a down term. I'm still working full time and plan to work part time next year, so the W-bucket allows me not to change those plans and if I want to stop working altogether, even if the market crashes, I still have that multi-year safe bucket where I can let the market recover.
In any case, the safe bucket has allowed me to not worry about what the financial market has instore.

Retirement accounts are prevented from buying or exchanging into tax-free mutual funds through the electronic channels.

Wow, that seems very strange to me that a fund company would decide what is acceptable in your portfolio. I don't believe Schwab does that. I've owned a municipal bond ETF for the last couple years, PZA, in my IRA with pretty good results in total return and a nice 4.7% yield. I could be fooling myself but I think of it as lower risk than say corporate bonds.

@Puddnhead
For benefit of others: Fidelity Quarterly report, sectors report October 29.
Our house remains healthcare and tech. for the equity side, and investment grade bonds for the bond portion; with a cash position looking for a home in the next few weeks.
Lastly, as to your earlier question about about a muni fund in an IRA. I do not find a reason to place muni's inside an IRA. Below in bold is the Fidelity reply when one attempts a muni purchase in an IRA account:
The security you are attempting to trade is a tax-free mutual fund. Retirement accounts are prevented from buying or exchanging into tax-free mutual funds through the electronic channels. For more information, contact a Fidelity representative at 800-544-6666.
Good evening,
Catch

FYI: (This Is A Follow-Up Arrtcle.)
Fisher Investments founder Ken Fisher said there will be no lay-offs at his Washington state investment firm despite some $3 billion in withdrawals by pension funds and others over allegedly sexist remarks he made at an investor conference.
In a local newspaper column published late on Friday, Fisher wrote that most of the firm is growing based on business from high net worth individuals, retirement savings plans and foreign institutions.
He wrote that growing revenue in those areas more than makes up for high-profile withdrawals from state and local pension plans and other clients. The withdrawals totaled more than $3 billion as of Friday as systems in Texas, California and elsewhere withdrew money.
Regards,
Ted
https://www.reuters.com/article/us-funds-fisher/ken-fisher-says-no-lay-offs-despite-withdrawals-over-his-remarks-idUSKBN1X71OY?feedType=RSS&feedName=businessNews&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+reuters/businessNews+(Business+News)

Absolutely not. I'm 100% all in stocks (via mutual funds). This bull has another 15 years to run fueled by demographics and technology. Of course, there will be corrections along the way, some of them steep, which the doomsters will proclaim (as always) as the end of civilization, but I'm having none of that nonsense.
I believe right now is a great time to be buying risk assets - perhaps more so than in 2009. Stocks have essentially been building a mighty base over the last 18 months in preparation for an explosive move higher that will continue for years to come. As the stock market is the most efficient leading economic indicator, I simply cannot see a recession next year or for many years to come. A cursory glance at a basic S&P500, Dow, or Nasdaq chart supports this point of view. Are they collapsing or on a terminal downward spiral? No.
Note: I speak as a 53 year old with at least 10 years to retirement. My circumstances and outlook may be different to yours and I encourage some degree of diversification no matter your age.

The best "retirement" account available if used correctly, IMHO. Tax free money in and tax free out. Using correctly for retirement would mean to let it build, don't use it for medical expenses until retirement. I believe you can even pay your Medicare premiums with it.

My usual comment.
For most investors, buy and hold a simple target fund is one of the best. I believe you can do worse.
For above-average knowledge investors, there are several other good options.
I see stocks as a simpler portion of one's portfolio. The US LC is the dominated category and SPY/VTI is a pretty good risk-adjusted index. The biggest difference is the bond portion and the older you get the more you should pay attention. For most, it's several years prior to retirement and thru retirement.
Bond land has opportunities such as Multi sector and Non trad bond OEFs and all the way to leverage FI CEF. These funds have much higher dist and in most cases reasonable risk attributes (SD, Max draw, Sharpe, Sortino). Examples: PIMIX,SEMMX,IOFIX,JMSIX...PDI,PCI.
For about 20 years I have used best risk/reward funds.
I can name several for stocks/allocation...PRWCX,USMV,SPLV and maybe DSEEX, AUEIX...recently I looked at international stocks and came up with MFAIX/MFAPX.
Most/all of these articles, opinions and research papers are discussing simple bond funds which are planes without a pilot.

@hank and I, and maybe other MI residents receiving retirement benefits from our state, will now have about $600M of the pension fund administered in house. I have no idea if Fisher's company did well for us or not (see Lewis' comment above about performance) nor will I be able to assess how the new managers will do with that chunk of change.

History may make me look foolish but I don't think the market will be in serious trouble unless and until its clear that Trump will leave office which seems unlikely in the next 6 months. Since you are conservative I would go with 25% oakbx 60% the capital preservation fund and 15% the PIMCO fund or other fund you think looks best.
You will surely be following Buffett's advice
Rule 1 Don't lose money
Rule 2 Don't forget rule 1
remember that even when conservative your retirement account should provide a real return (i.e beat inflation)
I think my suggestion will meet that goal and I hope your desired future investments will do that.

I had my 401 set up as you suggest until recently.
The question I asked was:
''Which funds of my 401 choices would you leave money in the next 6 months.''

Got it. You're not asking about portfolio allocation, just fund selection. There's no apparent reason to have significantly different asset allocations five months from now (pre-retirement) and seven months from now (post-retirement).
But the specific funds you have available will change in six months, when you roll over your 401k. So you're asking about funds to use now for the next six months given your target allocation.
(If it helps you feel better, you might check to see whether your plan allows in-service distributions after age 59½, assuming you're that old. Then you could just move the money now; end of problem.)
Frankly it won't matter which 401k funds you pick. They are all respectable.
Whether you get your chosen large cap domestic equity exposure by using VFINX or a combo of AMRMX and VIGRX won't make a big difference. Whether you take one of these options and add PTTRX for your bond exposure, or use OAKBX for both stocks and bonds won't make a big difference either.
Building on @MikeM's comment - if you have a stable value fund that is paying as much as an intermediate term bond fund, that might actually be a better choice than PTTRX or OAKBX for bond exposure. Long term (the past year was an anomaly for bonds) that could give you similar returns with less volatility. You could roll over your other assets while leaving money in the stable value fund (if that's what you've got) when you leave.

@Art, you may not want to take much risk with your nest egg just before you retire, so I would be inclined to go conservative the next 6 months until you are able to rollover and set up the portfolio the way you want it for long term retirement. Yeah, you may miss a little upside but you may be more unhappy to lose what you thought you planned to start your retirement with. Just my 2 cents.
For less risk, I would just keep OAKBX and get rid of the other funds. Not sure what a preservation fund is, but if it is similar to a GIC I would split between that and the balanced fund OAKBX at whatever percentages you're comfortable with.
Good luck.

Hi @Art, (FWIW) I'd say you are conservatively invested at about 70% (cash & bonds) /30% (equity) more so than me being at about 60% (cash & bonds) /40% (equity). With this, you know your risk tolerance better than me. I'd would stay invested along the lines of the long term asset allocation you plan to use going forward in retirement. I'm also thinking the asset allocation is more important, in the near term, over fund selection since you will be reconfiguring your portfolio in six months or so. For me, though, I'd add some small/mid caps along with some emerging markets and follow a global mix of about 70% domestic and 30% foreign. I'm thinking there is presently better value to be had in foreign equity over domestic; but, I would not venture to far towards foreign.
However, some say, you really don't need foreign holdings since about 40% of the revenue found in the S&P 500 Index now comes form abroad. Perhaps so.
I sincerely wish you the very best in the years ahead.
Skeet

I would ask myself how would I feel if the date you moved the funds coincided with a 20% bear market and you had lost a chunk? There is an increasing awareness that people who loose large amounts in early retirement bear markets sometime don't have the confidence to stay in the market for the comeback. The next time it may not snap back like it did in 2009
Consequently I would lighten up on the developing markets and stocks

I am retiring at end of March, 2020. Fund choices in workplace 401 are few. I am slowly exiting existing positions in order to preserve principal. Once I retire I will move monies somewhere where my options are more suitable for a someone in retirement. My question is, Which funds of my 401 choices would you leave money in the next 6 months.
AMRMX, VFINX, VIGRX, OAKBX, OAKIX, FSCCX, VMVAX, PTTRX, ODMAX and a preservation trust fund.

FYI:(Slide mouse to 37:20 minutes for Bernie Horn interview.)
Bernie Horn, portfolio manager at Polaris Global Value, says that while the U.S. stocks have sharply outperformed international stocks since the financial crisis of 2008, the situation has now gotten to where foreign valuations are increasingly attractive, and he noted that if you can find the right valuations in businesses that are able to grow cash-flow over time, the stock should ultimately pay off no matter where in the world it is based. Also on the show, Tom Lydon of ETFTrends.com makes an actively managed municipal bond fund his ETF of the Week, Pat Rowan of TIAA discusses Americans' confidence in retirement, and Craig Curlop of biggerpockets.com talks about his new book on 'house-hacking,' a strategy where you buy multi-unit properties, live in one unit and rent the others, uing the rent to pay your mortgage and effectively letting you live without having to make a monthly housing payment of your own.
Regards,
Ted
https://www.stitcher.com/podcast/moneylife-with-chuck-jaffe
M* Snapshot PGVFX:
https://www.morningstar.com/funds/xnas/pgvfx/quote

FYI: In a comment responding to my recent blog post about making better decisions in the face of uncertainty, a reader wrote: “Life is inherently risky. To try to compensate for every contingency is irrational. We can “what if” ourselves right into a straitjacket! You retired early … you won!”
Regards,
Ted
https://www.marketwatch.com/story/nearly-2-years-into-early-retirement-heres-all-that-ive-gotten-wrong-2019-08-19/print

I always enjoy reading Dr. Madell's perspectives.
Because of possible downdrafts in the stock market Old_Skeet, now retired, carries more cash than perhaps most. There are several reason for this. They are 1) it provides me an additional safety net should I need additional cash for unexpected expenses where I don't have to sell securities in a down market and 2) it provides me the ability to do some equity buying during down markets.
I'm now running what I call my all weather asset allocation (20% cash, 40% income and 40% equity) because it affords me everything necessary to meet my needs now being in the distribution phase of investing. The benefit of this asset allocation is that it provides me sufficient income, maximizes my diversification, minimizes portfolio volatility, and provides for long-term returns.
The 20% held in cash area provides me ample cash should I need a cash draw over and above what my portfolio generates plus it can provide the capital necessary to fund a special investment position (spiff) should I choose to open one during a stock market pullback. In addition, cash helps stabilize a portfolio during stock market volatility.
The 40% held in the income area provides me ample income generation to meet my income needs in retirement. It is a well diversified area that incorporates a good number of income generating type mutual funds.
The 40% held in the equity area provides me some dividend income along with some growth that equities generally provide which helps offset the effects of inflation.
Generally, for my income distributions, I take no more than a sum equal to what one half of my five year average total return has been. In this way principal grows over time.
Over the past five years, or so, the following years were up years for me. They were 2014, 2016, 2017, and thus far 2019 while 2015 and 2018 have been down years. With this, I now govern and invest with more caution than I did years back when I was in the accumulation phase of investing and had a higher allocation to equities.
So, for me, Dr. Madell's comments in this months newsletter offers up some good old sage thinking and wisdom. Hopefully, it will for you as well.
I wish all ... "Good Investing."
Old_Skeet

Thanks John. Not much I haven't heard here but some really good suggestions bulletized in one place. One they didn't mention and I intend to use next year is working part time in retirement, both for the extra income and the social aspect that I enjoy.