Furthermore being all the way east, you are most assured to end up fighting the mongols and timurads late in game. This can make the inital expansion slow, and the long distances cause rebels to be a more continual pain. Russia starts off very small (1 place) and all the nearby rebel cities are greatly spread out. I'd only say porugal hardest of the western european nations, but the hardest would have to be chosen out of russia, turks or the byzantines.
