Tactics against Haven and Dungeon.

Anyone. Having a large army won't be a problem here => Death and Barbarian.

In general, the growth rate of creatures for the Academy is low (except for thieves and level 2 units). You can overwhelm them with numbers... But it depends on the situation. You need to build and buy the Chaos Dungeon, which takes time and money. You can attack Chaos then, while it hasn't had time to buy the Chaos Dungeon.