Like others I run HK(L and omega leadership), 88, 86(omega basic and assist attack), JE (halfway to 7*, everyone else is 7*) , and then GS; JE, GS and 86 are G9; HK and 88 are G8. I have been doing pretty good with this team and before JE with my Poggle team I ranked in top 100, now I average top 50 and can get into top 20-30 for payout depending on how the Dooku Dodge Leadership treats me(having terrible luck these past few days, 88 hasn't landed his aoe on anyone so far). I am going to start farming IG-100 to replace GS and then when I face double taunt and sometimes RG I sub in my Mace (need a droid caller for G9 and subsequently he'll be G10 as he's easy to gear), and I sub in my Jawa against other JE Droid teams (there are 2 others on my sever) so I can stun them all (or at least some) before they go. This comp is good and I would recommend it. It is not meta and it's not P2P like B2(not slamming you guys, I'm super jealous that's all). All characters can be unlocked and starred fairly quickly, and depending on how often you do T7 and what your rank/RNG is like for rewards, you should end up with a fairly decent squad to compete with and should be doing well in arena. I do understand your pain on JE assisting 86's special and I hope that CG do something about his detonator (or at least boost his potency so it's not resisted all the time).
