more than a half stack of Orcs attacked me while I was sieging. I thought I had killed most Orcs around Dain's Halls so I laid siege to the settlement. So I roamed around Dain's Halls for 2 turns killing another 2 reasonably sized armies. That way you don't have to fight everything at once. In my opinion it's way easier to kill all of the small AI armies around settlements before capturing the settlement itself.
After taking it I encountered a reasonably sized army of the Orcs of the Misty Mountains, which I easily defeated.
So starting the campaign I sent Dain, Balin, a unit of Dwarven Axemen (the halberd guys), a unit of Dwarven miners and a unit of Dragonslayers to the Wormcove, the little settlement north of Erebor. I like to take a lot of settlements early on to start off my campaigns. Story time! I am playing a Dwarven campaign in the Third Age mod for Medieval 2 with the MOS submod.