No, you're not automatically allied or become a vassal, it is the other way around, she'll join your clan. You don't get any armies! Your wife is a free companion (doesn't count to companion limit) with very good equipment, some are good fighters and army leaders, too. They are also good for governing fiefs, but their main "job" is creating heirs.Ok I’ll marry on my next playthrough. What are some main benefits for marrying? Does that essentially mean I’m allied with my wife’s faction? Getting their armies under my clan too?