3. Just Don't Open The Bunker Door
So you have this army of elite fighting Imperial units along with a squad of AT-ST scout walkers and you somehow still manage to be defeated by an army of retarded teddy bears. However, you still have one advantage left. The bunker your army was supposed to keep secure cannot be opened from the outside. Knowing this you shut the door and lock it tight. There is no way in and that's a good thing because inside this bunker the shields for the not yet completed second Death are being housed. The job is pretty important, as without shields the Death Star is vulnerable to attack from smaller fighters who can fly in and blow up its reactor core (see #2), which means that until the rebels on the ground open up the door to your bunker and destroy the shield generator the rebels above in space are sitting ducks and doomed to failure. So then you get a message saying that the battle is over and the opposing forces were crushed along with their talking stuffed animals and are fleeing into the woods. Since you didn't monitor the battle or take it into consideration, you think, hey, why not send a few squads to open the freakin' door? The impenetrable door that didn't need to be opened for any reason. And that's how the Empire ultimately lost the galaxy.