So, I played Muscovites... I cultured and conquered my way to 20% land as the UHV2 said, no go. I then conquered Amsterdam and hooked up Atlantic Access for UHV3, no go. Then I conquered Istanbul as UHV3 said I could (Conquer Constantinople or control Atlantic Access), no go. Then I increased land to 25% and won a domination victory...
tl;dr Muscovite UHVs 2&3 are broken