well lets start with while Captain Gilad Pellaeon took command of the imperial force at endor it was only to order a retreat. as for the 12 Grand Admirals. while thrawn was not one of the first 12 he was promated to Grand Admiral after Zaarin proved to be a traiter and thrawn hunted him down.(through that was just when he was givin public promotion to Grand Admiral, he was already a grand admiral by that point). back to the story, while im not to sure about the rebel part of it, i like the idea of the empire being split up 12 ways, with each of the different Grand Admirals taking a piece. maybe giving each of them a Executor-class star dreadnought.