[Vicious Love]

This might be far, far more trouble than it's worth, but would it be possible to dissociate modded nations from existing nations altogether, and have a game's host choose which nation overwrites which in a given game?
This wouldn't work for existing mods, since most of them edit existing units in addition to adding entirely new ones(Hero editing would otherwise be presently impossible), but this seems a small price to pay for the convenience and versatility this sort of fix would afford.