In the latest Version of Starfire (4th edition or "Galactic Starfire") they have this feature where the equivalent of SE4 "AI" empires (called "Non-Player Races" in Starfire) have governments of various types. There are a bunch of Groups of related government types, and at first you don't know the exact government type just the group, but the exact type affects their behavior including responses to treaty proposals from you. There is an additional possibility, regardless of government type, that their leader is "insane" and will do random erratic things.
So, maybe there is an undocumented "insane leader" feature in SE4 as well
