A key part of the sPvP is match making, and you try complicated algorithms trying to make the match making balanced. But, I mean, why in so many games there is one side with FB and scourge and the other side maybe have a core guard. In this case, in this meta, the game will be very imbalanced by the comp itself, even if the skill level of both games is somewhat balanced.
This is a big problem. I think a FB can compensate at least 50 rank point differences, especially when one comp is FB + Scourge and the other is Core guard/ DH + Scourge. this is part of the reason why the sPvP is not fun. I have numerous games this season where the other team has scourge + FB and we have nothing, and its very hard to fight because in ranked where people cannot communicate effectively even plat 1, 2 people dont know how to rotate and try to avoid teamfights. Yes, there are games where the other team have scourege+fb+scrapper. Totally not fun, and at this comp, its not about skill, its about the comp.
Also, should stop allowing people switch to heal amulet/rune etc after pop. but people are free to choose other classes. This would address most of the downsides of completely ban switching classes after game pop.