I don't see zombies as overpowered. I went back to playing as Solar Flare and am winning easily too. Granted it's not the best Hero deck but I am not fixing what isn't broken.
The only really overpowered Zombies deck is Neptuna since it is insanely tombstone deck.
I just won a game against Impfinity, knew it would use the chickening bit by then, I planted my push shrooms and 2 buff-shroms and he couldn't so much about it. You have to anticipate what they may do. See that they have 3 brains left, assume they have weed spray. See they have 4? Assume they have chickening. You don't plant, they don't plant and the next round is a draw.
I do agree that Chompzilla is probably the best, I just have to do better with the my card deck 🙂