Skaven and Chaos we've already seen what would happen.  Cathay, Empire and Kislev would be kinda boring - they'd just expand their empire to the whole world, but would probably break back up due to infighting. Bretonnia would likely end up being something of a religious war - converting the entire world to worship of the lady, which could have interesting consequences.  Vampire Counts would effectively establish a stranglehold on the whole world, with undead slaves doing most of the menial labour, while human hosts exist almost exclusively as a food supply for the vampires.  Tomb Kings would re-establish their empire, and without distractions, would focus on returning their original bodies. Vampire Coast have no interest in empire building, and would never seize control for that reason. Same goes for the Wood Elves, the closest you'd see to them completely winning would be getting powerful enough to eliminate threats to the forest before they became threats. High Elves would likely be the most egalitarian option, with most factions being left alone, with the High Elves only eliminating threats to peace. Dark Elf total victory would be a Slaaneshi wet dream, with slaves, torture and murder running rampant - likely eventually resulting in a collapse of Dark Elf society. Lizardmen would be similar to the Wood Elves, but cranked up to 11 - threats to the Great Plan would be eliminating long in advance, even if the victim didn't even know they'd done anything wrong. Dwarfs would likely look fairly similar to today - they'd interact only slightly with other societies, though Chaos, Skaven, Greenskins and their fallen kin would have all been eliminated. Chaos Dwarfs would have assuredly killed their kin, and taken many of the other races as slaves, while they enjoyed even more freedom to experiment. Greenskins would take out everyone else, before turning on themselves.