Sacer Bubonicus
Banned
Novgorod was a peripheral player in Rus politics, for the same reason that it was a mercantile republic. For it to unify Russia, it would have to somehow overcome this limitation, at which point it would become just like all the other Russian principalities: an agrarian feudal kingdom dominated by the rural nobility, because fertile farmland = more $$$ and more men for private armies.Novgorod would probably be unifier of Russia and perhaps Russia becomes more European nation.
What taking Genghis out of the picture would do is prevent Lithuania's rise to dominance in the 14th century, which only came about because it was able to sweep up the broken remnants the Mongols left behind in the south, and that Smolensk and Chernigov become good contenders for unifying the Rus principalities.