Are you talking about gaming ?
Or about real life ?
I agree with Europeans being more confrontational. Not all of them. Because there is no "European" stereotype. People in Finland are more different that people from Greece or Portugal than any two people in North America. But yeah, some of them (especially from my country) can be very direct. Americans are always trying to be polite first. Beat around the bush. And only in the end they say stuff they want to say.
But confrontational does not mean starting a fight. Maybe some Americans feel that way. But you can be to-the-point without having aggressive intentions. I am direct. I guess. I was told in the past that I was very direct. But I never try to start a fight. (Talking real life now. A good fight on a forum can be fun some times

).
But we were talking gaming. Again, it's just a hunch. I've been to the US in real life. (Many times. Even lived there). But I've only played games with Europeans. But when I look at forums (e.g. the US WoW forums vs the European WoW forums), I definitely feel the american communities are more toxic. More guilds in the US blowing up because of drama. That sort of thing.
That could have an impact on success.