Suggestions on avoiding collusion on Grand Arena

Absolute paranoia. First of all, nobody even knows who your two next opponents will be because it depends on the outcomes of the coming matches. The only way anyone could even do this is if all 7 other players ganged up on you, which is a ridiculous suggestion.

Secondly, you can literally look at everyone else's roster. You already know what teams they have. Sure, you don't know where they're placing them but you know what you're up against.