Russians dont really like playing with other russians (i recall hearing, from wherever), and also from some other dude i heard they get a poor ping on the russian(swedish) server, which leads them to eu. Its really baffling what mentality they jump into EU with, but then again, its seems like almost the majority of dota are russian players, i mean its an insane amount. Like putin told them to play it. Many times i watch twitch, and the ru stream tops the english one in viewer numbers, even when navi isnt playing. So them assuming people are russian, or atleast teh majority, does kind of make sense. Everytime i see one speak russian, theres always one to answer.