I noticed that the New Republic in my Imperial campaign never tries to kill Sander Delvardus even though they have the Eriadu Authority basically defeated, and I'm pretty sure he still has his normal Star Destroyer. In another older campaign of mine the Thrawn Clone was in a tiny fleet and for some reason the New Republic didn't attack him. The AI always seems to avoid attacking leaders, and I've only ever seen them attack my leaders twice. I think this should be changed because I would find it much more interesting if the Imperial AI tried to actually get the Dark Empire instead of sitting around doing whatever.