Usually either the Spanish or Almohads do really well if left to their own devices for long. I usually try to get on the Iberian peninsula fairly early to prevent one of them from getting too large. In my current Danish campaign, I got side-tracked into central Europe, now the Spanish have the whole peninsula plus north Africa all the way to Cyrenicia. I'm allied with them at the moment, but I can't let them go for much longer, I already see stacks of Jinettes growing.