Ithink short, limited wars for economic gain, changing allliances and an AI that sues for peace when that is opportune is a very good thing.

remember, medieval warfare was not WW2/WW1 where the sides were set, and everything was fought to the bitter end as some kind of total clash btwen ideologies and civilizatins. instead warswere short means to an end, and were seldom continued when there was nothing to gain from it. also, factions ability to conduct polonged campaigns were limited, as money was short, logistics were not to good, noble support not endless, and the farmer levies were needed back in their fields.

I was always infuriated by the med1/rome AI habit of fighting to the bitter end, no medieval royal family would do that, they would sue for peace before they lost their base of power, and when they knew nothing further colud be gained from war.