Slitherine

I don't know if there's even a way to prevent this, but I feel like any playthrough, pagan, Christian, Muslim, and Hindu all blend together. ai aggression forces you to either be a vassal or conquer the entire world, almost. Is there any way I could curb their aggression, or is the focus to form the largest empire you can? I find the larger blobs less enjoyable and far more time-consuming than city-states. Maybe I need to lower the difficulties; if so, I'd love to know if the impact is significant or it's by design this way. besides that, the trade incentives, religion, culture and war are great. I just dislike the repetitiveness caused by aggressive continental powers in 1100 AD

I would say that, in addition to playing on Balanced difficulty (and not higher, which increases AI aggression), the most important point is really to work on (and make an effort toward) maintaining good relations with your neighbors and even with more distant nations. It is possible to develop in an optimized way with relatively few regions, but this requires investing a fair amount of resources into favorable transactions with surrounding nations (through gifts). There is never any war between nations that like each other...

Im playing my current game as England at the Experienced level, AI aggression set to balanced.

My main army is mucking around in the middle east, but since I've invested fairly heavily in having good relationships, nobody back in Europe is attacking or putting claims on me.

I currently control England and most of western France, along with northern Spain. Scotland, Wales and France are all very friendly to me.