Taylor is famous for his "There's more than one road to Dublin" comment, and that comment is so appropriate here, too.
Location is definitely important and the wiki here will help a great deal. The concept is not too hard: if you wind up shoveling in all those equity funds to your tax-deferred accounts, you will eventually have to take them out. When you do, you'll pay income tax on everything you take out. If you keep those equity funds in a taxable account, you'll only have to pay capital gains when you liquidate that money. Hopefully, capital gains tax will always be less than income tax rates. Likewise, if you put your fixed income in your taxable account, you'll pay income tax on the monthly proceeds whereas if you put fixed income in your tax-deferred account, you simply "defer" those taxes.
Overall, this is just smart and, as a rule, it's the right way to manage to biggest chunks of your investment accounts. But you don't have to be so rigid! Say the stock market really tanks. There is no problem whatsoever selling some fixed income in your IRA to buy equities; in fact, it's a good move. You can start feeding new money into equities on the taxable side but you've not generated in capital gain but selling in the IRA. You can rebalance later when the market allows: you can start selling back those equities in your IRA to buy FI when your asset allocation allows.
And things aren't quite as "efficient" as they once were either. Munis are only for taxable accounts and they've become even more valuable, at least to me. But equity dividends aren't "free" and are currently higher than a lot of bond fund dividends (for example, even for the tax-efficient TSM, I'm going to be getting about 2% dividends but paying 15% [federal] plus 3.8% [Medicare surtax] plus 12.3% [state tax].)
Also, there are some 401k's where the fixed income funds have expense ratios of over 0.75%, sometimes even more. With fixed income, that's deadly so you might have to think outside the box.
Everyone's situation is different, the guidelines here are pretty common sense, but there's plenty of room for maneuvering.