It's just Eastern Euro/former Eastern Bloc style boxing. it's not magic Russian Superman techniques or anything, just the way they fight.
who knows where it came from.
I'm not the best person to judge as I am a total newbie, but I don't think it's necessarily about sloppiness, just a different style.
it offends our sensibilities about boxing, but judoka doing heavy lifting and developing a "power judo" game offended the Japanese back in the 60's.
The Russians have their own traditions of fistcuffs from before the introduction of Western/English boxing, and I'm pretty sure they do fight on ice on occasion.
I seem to remember there was some kind of traditional mass fights they did on deeply frozen ponds where different villages would beat the shit out of each other for fun.
it may just have been the personal style of some important boxer who spread Western boxing in Russia, and it stuck.
punchdrunk showed me the basics of the Eastern Euro hooks he learned from a pretty high level Eastern Euro boxer.
He knows American and Eastern Euro style, and picks what he thinks is appropriate for him.
Cubans had access to quality American trainers before the revolution, and after the revolution, high level Soviet and (to a lesser extent) Mexican trainers.
so, I would guess they are sort of a melting pot.
you might want to talk to KidJustice too, as he has trained under the Eastern Euro boxer and trained with punchdrunk as well. He also knows U.S. and Eastern Euro style.
both punchdrunk and KidJustice have more experience and can talk about it better.