Personally I see 3-2 zone as a counterpart to M2M, not to 2-3 zone. In my mind 1-3-1 zone and 2-3 zone are the real counterparts. I agree that those 2 and box defenses need a fix so we would see more differently built teams and argue more which tactic is overpowered rather than just arguing between M2M and 3-2.