I run:
Qi'ra
OT Chewie
Han (w/Guard)
Nest (w/Guard)
L3 (kinda....)
I prefer to run L3, but I've found that Thrawn makes tackling Jedi much easier. I switch between L3 and R2 on defense, but R2 tends to do a bit better.
If I didn't work during payout (can't wait for that update) then I could hit top 20, sometimes 10 with good luck. Revan squads are all RNG - I win if nest gets marked, otherwise I lose. All other teams go down easy on offense. If I do make top 20, I typically fall to upper 30's or 40's.
Im hopeful that Canderous or maybe a future Carth Onasi will boost the scoundrels. Canderous' possible damage is interesting, but we will see how that plays out. His triple attack on basic could pair really well with Qi'ra assist call.