Just as I've mentioned previously and the point of the whole conversation which you're completely missing because you didn't read thoroughly.There is already a total world market etf. It is used by the two etf strategy along with a bond etf. The vanguard total market etf is VTI for US and VXUS for international. The two etf strategy is talked about on www.bogleheads.org
It makes more sense to group the countries together rather than grouping all the stocks together.
If you group the countries and indexes and sort those by market cap, you gain 50 basis points a year.