Are the northern tribes supposed to field 7+ full stacks of units?

So as the title says, I've hit a snag of sorts in my Empire campaign, I dealt with Chaos ages ago and found them to be a nice and fun challenge, the northern tribes/Norsca however are not.

They somehow manage to have over [7 armies filled to the brim with units.](http://i.imgur.com/5x4DMhe.jpg)

[Most of them are higher tier troops for the factions, yet they show no signs of low income.)](http://i.imgur.com/hboFE0H.jpg)

At this point they feel like nothing more than a chore: Kill one stack, two more appear, kill those two, three more appear ad infinitum.

[And on top of that, they have no agreements between themselves. ](http://i.imgur.com/6NBI08o.jpg)

Are they really supposed to be like this? If they continue on like this they will end up being a bigger threat than chaos ever was in my campaign. As I have no good way to attack their settlements, I've tried twice now, only to have my armies crushed by four fresh gold chevron armies that spawn out of thin air.