If that were to happen, women would be literally at each other's throats for even the worst dregs among the 10%.

I think what would end up happening is the exemplification of the fact that over 80% of all women ever have had kids, but only 40% of all men have had kids, and the top men would have massive harems, while the bottom men get scraps. But what Imp thinks is that they'd all become political lesbians and keep all the men as breeding slaves.