So I finally beat this. All of the strategies I could find didn't account for recent AI updates. So, here's what I did... as best as I can remember:
Snipers are your friends, they can shoot turrets from far enough away that the healing droids don't get shot behind them!!
Drop sacrificial blaster troop inside near upper turrets. This draws out all troops and hero. Dropped sniper near upper left with droid behind him. All troops and hero will head through gate, hit them with striker there to wipe them and just leave hero. After a bit, dropped Leia & Chewy to polish off hero & turrets. Then dropped sniper in upper right with droid behind to take out those turrets. Then drop the other snipers and let them work away patiently... At this point, I don't recall exactly who or what I dropped where but I managed to 3 star with 30 seconds left