Win condition: Rout the enemy
This shouldn’t be too tough, even if you’re underleveled. Most of the enemy force will attack from the north, so block the middle passage with a durable Knight and weather the storm. Your ranged units can help out from behind.
You’ll also want to take out the Arcanist with Mire as soon as possible – either get up close and personal and defeat him immediately (careful of archers, though), or wait until he actually approaches before doing the same.
Eventually enemy forces may loop around to attack from the south, so send another Knight or other able unit(s) to take care of it. Rout the enemy to clear the map.
