Ok so for people struggling with tier 1, i finally found a way to beat it if you don't have a super geared druid team (or aren't a fat whale/dolphin).
Snowtrooper is key, in particular his 3rd passive ability, Assault training, make sure you level this to at least level 5 and run with an all empire team. It makes it so that when you defeat an enemy he gains x% turn meter and at level 5, ALL empire allies gain half the amount.
The turn meter gain from killing the expendable ewoks should give you enough tm per revive to out pace the ewok elders.
My Snowtrooper is only level 60, g7 but I used him purely for that. Obviously you'll need some luck and hope the ewoks don't target him. But this is the best way I've found to finishing it and I've had over 80 attempts at it previously with no luck.
My team was: palp lead 7* g9, Vader 7* g9, tfp 6* g9, Snowtrooper 5* g7, ig88 6* g8(probably could have gone with rg now that I think about it).
Respective levels: 74, 72, 80, 60, 72
No zeta on Vader, only character in my line up with omega ability is palp for his leadership
Hope that helps