Finally finished it with Chirpa, Elder, Paploo, Logray and Scout all at G11.
I tried to drop speed off them and go with health and defense mods with crit avoidance arrows to survive the opening rounds better. I found it didn't make much difference and was pretty random. So I put my speed mods back on the Ewoks and re-started until I got a scenario where Chewie didn't have stealth and my squad was mostly intact after the opening salvo. It was hard to keep them off Elder without Wicket to stealth him. Several times I had Chewie down and was working Han down when I tried to protect Elder with Paploo's taunt but C3PO threw confuse on him right before his turn so he couldn't taunt and then they killed Elder. I ended up having better luck with speed to get more attacks, heals, dispels and debuffs in....you want to get Chewie out as quickly as possible. They have so much possible offense in terms of crits, potency, and debuffs that defending against them is pretty random.