Rex was my MVP for this fight.
I got trashed the first time when I went in with a starting lineup of:
Biggs (7 ship, 7 char, G10)
Wedge (7 ship, 7 char, G11)
Asohka (7 ship, 7 char, G10)
Ghost (6 ship, 7 crew, G8 crew)
Phantom II (6 ship, 7 crew, G8 Chop/Sabine, G10 Ezra).
As reinforcements I had:
Fives (7 ship, 7 crew, G9)
Poe (7 ship, 7 crew, G11)
Rex (7 ship, 7 crew, G10)
I learned in that first fight, though, that the enemy pretty much doesn't buff at all. Not like fighting in the arena versus a taunting Biggs, a buff-spamming Plo Koon, or a Retribution-granting Tarkin or Maul. So I swapped Asohka and Rex, putting Rex in the starting lineup and saving Asohka so she could have a crit-guaranteed special on reinforcement to do 50k+ damage.
But it was actually that combo of Rex plus Biggs that won it for me, I think. Rex was able to get two of his specials in to restore Biggs' protection, and Rex' basic doing target lock on unbuffed opponents also kept Biggs topped off in protection. The extra few target locks from Biggs also made Ghost's attacks more effective, and I think I got one or two times where one of my ships resisted a debuff and triggered Rex' unique that gives people protection recovery.
Because of Rex, I went into the third round nearly full of health and protection across the board. I did lose someone there and brought Poe in to finish off, but 2 stars still gets you the 15 Ackbar shards. :)