Tactics against Haven and Dungeon.

Chaos is the most difficult opponent, in my opinion. Because the hero simply has a lot of direct damage spells. And when your army is dwindling before your eyes... sometimes there's no time for strategy and tactics. This is where the balance needs to be adjusted (Optimal, what does Equilibrius say about this, share your thoughts).

But if you play as Sylvan, the anti-magic spell can save you. And for Haven, energy drain will be useful. This is if you're directly fighting a Chaos hero.