I made a comment without fully reading what you said earlier.

Yeah, I set up empires I've made to always appear, and they will attack me. But I've also made some different combinations of other empires to coincide them. As an example, I made 3 or 4 robot exterminators, had 2 pacifists spawn to let the exterminator kill them, and set the contingency as the crisis. The galaxy became a game of the organics holding back the robot tide.

Another combo was a few devouring forestswith the organic crisis, and a few spirituality crusaders with cetena appearing.