Last night at my FLGS, we were talking a little bit about how letting commanders work for the enemy team could have some interesting results that in some cases would be more powerful than in their home faction. Some things I/we came up with:
Imperial Commanders working for Rebels
Admiral Motti
Improving Assault Frigate HP by 2 and MC80 HP by 3 seems pretty good to me. Limited utility with the smaller ships, though, who already have plenty of good Rebel commanders that help them.
Admiral Ozzel
Definite utility taking Nebulon-Bs from speed 1 "sniping mode" to speed 3 "holy crap, time to scoot" mode. Also has some utility when paired with plentiful Nav Team options (due to Rebels having a lot more Support Crew slots on their ships) to allow Nav tokens to be spent to change speed by 1 and improve yaw by 1.
Admiral Screed
Only real use is paired with MC30s, but it still feels iffy compared to the benefits they receive from Mon Mothma or Rieekan already. For the moment there's not a lot of benefit from taking a turncoat Screed.
Darth Vader
Vader works better with red dice (as compared to Screed), so he'd be an interesting choice with red dice ships that offer up enough dice and have a duplicate token they don't mind flipping to red. So I'd think Nebulon-Bs, MC30s, and MC80s would be more preferred here. CR90As already get the best benefit from the TRCs and don't really need any extra help there.
Grand Moff Tarkin
I'd put my money on Nebulon-Bs here. With Redemption and Engineering Teams on your Nebulon-Bs, Tarkin's Engineering tokens become 4 Engineering points every turn. He would also help Nebs Ozzel-style by giving out Nav tokens on the turn they take Nav commands to jet from speed 1 to speed 3. When in doubt, they can always just hold onto Concentrate Fire tokens to help even out the fickleness of red dice. Basically Nebs are cheap Command 2 platforms that can make decent use of just about any token and it seems like they'd love Tarkin. Conversely, you can pretty reliably issue Navigate tokens to a CR90/MC30 swarm and let them get in Concentrate Fires and other commands as necessary from their dials.
Rebel commanders working for Imperials
Admiral Ackbar
This is one of the weirder ones, I think. I could see using Gladiator-IIs here (because 1 red dice + 2 red dice out the side gives them a reason to be). He would also be a solid backup plan for VSDs where enemies get around the flanks. An enhanced Armament VSD + Ackbar is throwing 5 red dice out the sides, which is pretty impressive. Maybe it would be safer to stay in the front?
Garm Bel Iblis
Basically a cheaper Tarkin for a VSD-oriented fleet. Does all right with ISDs as well. Would seem to support a Rhymerball pretty solidly.
General Dodonna
I'm kind of split on this one, but I think overall you'd likely see Imperial Dodonna running a hybrid Raider/Gladiators + APTs fleet combined with a low-maintenance Rhymerball (Rhymer + Firesprays) to try to get maximum benefit from his ability. Overall I think Dodonna would be a stronger Imperial than he is currently as a Rebel due to the fact that you wouldn't need to choose between "fleet full of APTs/TRCs to try to trigger his effect, let's just ignore squadrons mostly" or "carrier fleet trying to get all the bombers in on something but none of these carriers themselves are great at triggering Dodonna's ability." With Firesprays you can have your APT black dice ships and your bombers without needing to worry about carriers.
General Rieekan
Oh my god, the insane things you could do with Imperial Rieekan. The obvious choice is atrocious amounts of Raider spam, but Gladiators and even VSDs would love getting in on some of the zombie bumper cars Rieekan action. I honestly think Rieekan would unseat Screed if he could be an Imperial, so it's wise that he's not 
.
Mon Mothma
Raider-spam time. I'm not really convinced it would work great, but might give the extra push needed to really explore what you can do with Raider-IIs, who live more comfortably in that medium-range "sweet spot."
I left off the wave 3 and wave 4 commanders because I haven't used them yet (or had them used against me) so it would be an extra helping of conjecture piled atop the current pile of conjecture, but I may get around to them in a little bit. I was surprised at how much Nebulons seemed to benefit from some of the Imperial commanders and how much more I'd consider VSDs with some of the Rebel commanders in particular.
So how would you use commanders that could turn traitor to your side? I'm just kind of curious as to what sorts of wacky fleet builds you'd see. It obviously won't (and shouldn't!) ever happen, but I find the pondering about it is rather enjoyable.
Edited by Snipafist