I just beat this one. Man been trying for a while and it was probably good RNG since Mace only reinforced two or three times.
Front lineup was
7* Jedi Consular - G8 - abilities maxed. Five dot mods (varying levels)
7* Ahsoka - G10 - abilities maxed w/ five dot mods (varying levels)
7* Biggs - G9 - missing one Omega w/ five dot mods (varying levels)
7* Wedge - G8 - abilities maxed w/ five dot mods (varying levels)
7* Ghost -
G11 Hera abilities maxed w/Zeta and level 15 5 dot mods
Kannan G8 abilities maxed except Zeta and five dot mods of varying levels.
Reserves
6* Resistance X-Wing (pilot at 7*) G10 with abilities maxed and five dot mods of varying levels.
6* Phantom II -
Ezra G11 w/Zeta - maxed abilities - five dot level 15 mods.
Sabine is G8 maxed abilities and no zeta. Five dot level 15 mods
Chopper G10 maxed abilities. Five dot level 15 mods.
7* Clone Sergeant ARC-170 - Clone Sergeant was G8 with no omegas (two abilities are only at level six) and Five dot low level mods.
I took out Rex first, then Ahsoka, then Consular, and finally the reinforced ships (all ARC-170's). Got it after third attempt today. Probably the hundred or so attempt in total. Hard challenge is hard.