Ive started as charlemagne, and it has been more annoyance untill now than anything else. factions all the times, and even when you become the HRE, everybody around you has a bigger army than you. You get an event to conquer saxony, and when you complete that, 1 second later 14000 rebel troops from widukind. Ad then the umayadds go for southern france (since muslims still havent been nerved)