@Ruyen - Can you get Luke up to level 78+ so that you can omega his abilities?
Crit damage for Luke isn't a bad idea, actually. CLS3 can be pretty brutal and if you're going to be trying multiple times for the right RNG, you might as well be waiting for a 32% chance of crit instead of a 38% chance of crit.
The thing about Stun is that so much of your early effort is spent on the Taunters, who don't really hurt you much if you don't stun them. Getting your stun to land isn't as important as getting an early kill.
When I finally beat this thing, it was after I got crits from both Luke and Han to start the first encounter. I had them both targeted on the Scout Trooper and just barely managed to kill him, then the taunts came. yes, taking a lot of hits, but they are puny hits and then if you get Han's taunt off with your 2nd Han action, Luke can start walloping people.
When Luke shoots the Taunters, have him focus on the trooper that started taunting last (kill that one and the other's taunt ends earlier & you're back to killing real threats sooner).
Without enough damage to take out Scout Trooper in your first 2 attacks (1 Luke, 1 Han), you have the hardest hitting enemy hanging around for turn after turn when you could be taking a lot less damage if he was gone.
Farmboy has always been useless to me, but I had a good set of speed + crit chance + crit damage mods on my Lando (crit chance set bonus, crit damage primary on the triangle, speed primary on the arrow). So in the morning I did GW, then I transferred my strong Lando mods, then I tried a bunch that day. Didn't finish. Next day I reset GW and did two or 3 nodes where I had no need of Lando so I didn't have to switch the mods back. Then later that day I finished tier 3 and moved the Lando mods back.
If you have a toon with speed + CC + CD, you might just consider moving that whole set of mods over.
and don't forget to level up your Farmboy.