Well I poured a lot more resources into it and got the perfect RNG run. I used:
Home One 6*: (pilot, pilot stars, gear, abilities, ship star, level, abilities, GP
Ackbar 7* g9 85 5/5/5/m, ship 5* 75 5/3/3/3/3, 26854
Wedge 7* g11 85 7/m/m/m, Xwing 7* 85 6/m/m 38208
Biggs 7* g11 85 m/m/7, Xwing 7* 85 6/m/m 37360
Ghost (all pilots 7* g8/9 80 skills 7/m) ship 6* 85 5/4/m/m/4 33814
Phantom (4/7/7 star g4/10/9 60/80/82) ship 7* 80 2/6/6/m/m 31697
Jedi Con 7* g9 7/7/7, ship 5* 80 5/6/m 27024
Reinforcements (all used):
Rex 7* 70 g8 5/6/5/5, ship 5* 82 4/6/m 21978
Ahsoka 7* g7 61, 3/3/3 ship 5* 75 19057
Bistan 7/4* g8/7 70/65, ship 6* 80 4/3/6/m 19601
At the start I was able to take out Rex and JC in the first two turns while keeping Biggs alive w purple assist health. Mace reinforced w Sarg, I took out Ahsoka, Mace reinforced JC, I took out JC, then battled through the 4-5 sarg's. Some key things that helped - I had 4 ships alive when Ackbar hit his ultimate. I believe I took out 1.5-2 sarges that turn. Mace whiffed his taunt on turn 1. This is vital. I believe he only reinforced 1 JC and 3-4 sarg's, so he may not in fact have unlimited reinforcements. He can definitely reinforce on a 0 turn cooldown timer though. Ackbar's level is more important than in the Mace challenge; he has to get the assists in to keep you alive.
A ton of luck was needed as this run (estimated 200-300th) they just happened to target purple shield ships, not focus anyone down, not get crits very often, missed some target locks, etc. I did use every single reinforcement and at the end it was Ahsoka and Bistan heavily damaged vs one sarge.
While I have beaten it, it is still extremely overtuned. I would suggest reducing all enemy ship HP by 30% or forcing Mace down to a 2-3 turn reinforce cooldown.