I like how Frosters are good against Blockades, and Pyromancers are good against Barricades.
But I think that division of good against wood and good against stone should continue.
Frosters are good against scull towers, but I think they should also be useful against Bomb Towers!
Now in the interest of balancing, I don’t think they should have a bonus against Werewolves (seriously the Werewolf is the monster of the cold North it makes no sense.)
Remember when you see a werewolf you grab your torch and pitchfork. I think werewolves should also be weak to fire. But again, a little balancing I’d give them a small resistance to poison since their monsters.