For anyone wondering:
Chewie and IG-88 only need to be 5* to beat (and 3*) the last tier of the CC Mod Chalenge.
On my third try (Chewie was being targeted all the time) I was able to beat it with:
Boba (L) G9 Lvl 76, Lando G9 Lvl 76, STH G9 Lvl 76, IG-88 5* G7 Lvl 70 and Chewie 5* G7 Lvl 65. As it is in the Credit Heist, you don't even need the last 2 toons, Boba+Lando+STH can easily solo it.
Now I'll get SF to G8 and STH to G10, and switch my team to: Wedge (L), Boba, STH, SF and Biggs (but I need to get some speed mods first, to allow my Boba and STH to be faster).
Btw, on my first 8 sims of the CC Mod Challenge, got 2 5* Crit Chance Triangles (and one of them with 3 speed). It could've been a Critical Damage, but I'll accept it lol