Confederations were introduced in Rome 2, but the way they worked never made much sense to me. In real life a confederation is like a group of independent entities that work together in a common cause. In the game though it was just like conquering except through diplomacy. The individual factions just ceased to exist. This is just fundamentally wrong in my opinion. That is a peaceful annexation not a confederation.

If possible I would like to see confederations changed to be more realistic and interesting. The way I think they should work is that it would be an alliance system between 2 and more factions. If one faction was attacked then all members would be called to defend it. If one member attacked an enemy then all members would be called to attack. Or something similar to that.