I've seen tons of AIs totally gimping themselves by making Protectorates of nations they should be annexing. Russia making Golden Horde into one, Mamlukes making Ethiopia into one, and even my own New World colony making a protectorate out of a one province minor Native American civ that was literally bisecting their territory. Oh, and when I declared war on the one-province minor, apparently my cultural kin in the colony sided with the natives? I'm assuming that's a bug.
The AI definitely needs some tweaks in this regard. For one thing, it shouldn't rule out attacking a protectorate who is weak or vulnerable, and it probably shouldn't make protectorates of civs which have a capital on the same continent as them.
The AI definitely needs some tweaks in this regard. For one thing, it shouldn't rule out attacking a protectorate who is weak or vulnerable, and it probably shouldn't make protectorates of civs which have a capital on the same continent as them.