I would add a smaller allocation to International plus perhaps an even smaller Emerging Markets index.
Disclosure: for the last 10 years I've steadily increased my foreign exposure, including to International Small Cap and Emerging Market, but the disconnect between US P/E and some foreign makes a stronger case than in the past. If you can tolerate the volatility--big caveat.
I sold Fidelity Pacific fund to Emerging Asia, by the way, at about one year before the absolute worst time to do so, based on the FidPac fund not moving for 5-7 years. Luckily Emerging Asia caught most but not all of the move.
For market inefficiencies to correct, you sometimes need a 1-2 decade patience fuse.
That is Buffett's advantage, I think, since he thinks in 10-30 year time frames. The lesson I learned from Buffett was to have a 3-8 year time frame, at least on areas where the market seemed misallocated. It's paid off when I had the patience to wait 5-10 years, usually with automatic monthly contributions, which lesson the sting unless the correction occurs quickly. Usually it took longer than I estimated.