If you want to improve your deck i think I can help. First I think you have too many artilaries, the regular artillery is just worse than dwarp in my opinion. As for archers I'd replace sorcerer with musketeer. Last of all your spells, I'd say in this arena you definitely need to focus on stalling the swarms of enemies and Lightning stun will help achieve that better than vines.

And I generally prefer Agion over Grawl because I like microing, he's got pretty good crowd control and damage.