I'm still shocked every time I get an email from coaches after the first recruiting cycle trying to split recruits we're both on. I've never even responded to them to tell them they're douchebags, but just make a mental note that they must be colluding in all worlds like that. To be clear, I'm making a distinction between trying to split recruits (collusion IMO), and messages where people basically "declare" who they are going after hard after we're both on them (not collusion, just dumb IMO).
Some of the guys have very dominant teams in worlds, makes it a lot easier to understand how they got them if they always avoid the random mid-level battles that are a drain on resources.