I think holding your age in bonds is a bad choice for anybody, early retiree or not. I forget the exact percentage, but I believe history shows that the US allocation that maximizes return over the long term is somewhere between 70/30 and 90/10 stocks/bonds. If you don't have much safety buffer built into your stash and you have a high percentage of bonds, inflation risk is likely to catch up with you before you die. If you have a good safety buffer, you can afford to ratchet down the stock market risk and hold a higher percentage of bonds. But you probably don't need to, because your safety buffer will protect you from sequence of return risk. Why not juice up your returns so you can leave more to your heirs or you favorite charity? In the low safety buffer scenario, you are exposed to sequence of return risk early in your retirement if you have a high percentage in stocks. But I'd rather have to go back to work early on than have to go back when I'm 80 because inflation caught up to me.
Unfortunately cFIREsim does not use international funds. However, a 90/10 stocks/bonds allocation when using only US stocks is NOT the allocation that maximizes returns.
http://www.gocurrycracker.com/path-100-equities/Look at the median end values. 100% equities is the highest.
I ran 60 year retirements with allocations from 75/25 to 100/0 in 5% increments. The median values were all increasing with increasing stock allocations:
$3.47M
$4.58M
$6.09M
$7.42M
$9.31M
$11.25M
The same trend is seen for average values.
Now as I stated earlier, this does not incorporate any international equities. However, international equities
in general provide a similar return to US stocks with some level of correlation. The developed markets are pretty well correlated with the US, and emerging markets are not well correlated. I have no reason to believe that adding international stocks would decrease portfolio returns for stock heavy portfolios.
It is well accepted that stocks in the long run outperform bonds. Adding bonds to your portfolio does not increase your total portfolio returns. The notion of "buying low and selling high" when you rebalance in a market crash sounds nice in theory, but it does not increase total portfolio returns because bonds lag stocks by too significant a margin when stocks aren't crashing.
The only reason to add bonds to your portfolio is to reduce the volatility of your portfolio. I don't feel like listing out all the numbers but the standard deviation of each portfolio tested above increased with higher stock allocations.