Mate, it looks like you've made some amazing progress with that collection. Wish I could say the same! I'm well short, but throwing an idea your way.

I have kept my FIRE/WATER at L5, but pushed my Obsidian - just for the reason of being able to get the Goblin Pyschic to Level 7 - at Level 7, he gets the SILENCE ability - and, all of a sudden, my win rate goes up ;)
(Ok, I also rented a cheap mushroom seer, and let the double silence destroy opponents).