I would say proxy strats fall outside the realm of balance because those games pretty much come down to whether or not the opponent scouts it in time. I hate it and j wish nobody dos proxy strats, I think they're lame. In the game where Dark opted for neural infestors, he could've won if he simply had any other supplemental unit other than roaches. Hydra/Ling combo would have done the trick. Broods would have shat all over it. You have a point about toss having a myriad of tools to end the game. That's how it's been since sc1. Zerg is just the reactionary defense first-race in the early game. They can easily dictate pace in mid game (like when dark went mutas and forced classic to stay home) and in late game, just as any other race can in certain scenarios. You are correct about early game tho. Zerg just isn't an early game race