I say China. Although the endgame point with Greece is perfectly valid, endgame seems to be pretty far off atm, unless you choose to use crowns to reach it. However with China, you don't really get any benefit at all in practice. The extra citizen is practically useless as the final number of them never quite fits for anything but hunting rabbits or an occasional forest clearing. The extra defending troops are the same thing. At the current point of the game, there are exactly zero players that don't spam archers so even if the bonus was much greater, this wouldn't have any real impact on the game. Finally, unique archers are a joke. By themselves, they aren't that bad, but compared to other nations' special units, they are desperately weak and, once again, don't offer any real advantage in the battle because of that.