-Rebellious AI never ending wars. It seems like when a nation is created through rebellion, it gets locked into a never-ending war (they seem to last for decades until some hard codded mechanic kicks in and while peaces out all belligerants) with their former over lord, where one or both sides refuse to peace out regardless of context (say, overlord is at war with 10 other nations, it seems logical to offer whatever to newly formed nation if it cannot afford to fight them as well, finish the current wars and then take vengeance, thats what i would do), instead they fight for YEARS until one side manages to completely annex the other or before mentioned guessed mechanic white peaces everyone.