VXUS < VXUS + A-shares, which changes the balance of it all. I can’t be bothered to research this exactly as FTSE doesn’t publish their numbers as clearly as MSCI.
You can learn a bit about A-Shares form this MSCI page:
Also remember that MSCI EM is not the same as FTSE EM. The largest difference is South Korea, which is classified as EM by MSCI but is Developed according to FTSE.
As to small caps - this worked before. No guarantee for the future. I don’t think it’s a big risk long term. Worst that can happen is you spend a tiny bit more on fees (VSS is 0.13% TER as compared to weighted 0.06% of VTI+VEA+VXUS).