ivesjl, your proposed fund-
Total Stock Market = 40%
Total Bond Market = 40%
Total International Fund = 10%
REIT = 10%
-is known as Rick Ferri's Core Four. It is one step up from the basic three and it's a very good portfolio, but just one of many good portfolios. Percent international is always in debate as to whether you need it or not. I think it's a good diversifier and Vanguard has done a study which shows optimal allocation is between 20-40% of equity. https://personal.vanguard.com/pdf/icriecr.pdf
Lifesoft's portfolio drops the REITs and adds more slice and dice instead of using total stock market and total international because small and value stocks can add a premium in returns.
The Coffee House portfolio slices even more by adding large value, small blend and small value. International is a bit lower than Vanguard recommends, and I'm not sure if small international was available when the CH was created, but today it might also hold small international.
It's pretty much an investor's preference as to how complex he/she wants to make the portfolio, Those premiums may not show up for long periods and there is something to be said for keeping things relatively simple. Slice/dice portfolios can be very effective if the investor can stay with them.
When times are good, investors tend to forget about risk and focus on opportunity. When times are bad, investors tend to forget about opportunity and focus on risk.