The Cagilian alliance has been expanding for some time now, so no one can accuse it of stagnating. It is, in fact, the main source of conflict and change. It's also in a precarious position, as it is composed of many separate realms, the heartland of which is in the centre of the continent. This gives it the potential for much future change as well.
Darka, on the other hand, is gigantic, and in the corner of the continent. They are a dominating presence, with a solid, practically unbreakable foundation, so I do not expect much change to come from them.