Team I use that seems to work

Job

Rey - amazing single target damage
Leia- great single target damage and crit buff
Chewi- taunt and self heal
Barriss- (leader) the extra health from leader ability allows me to survive some teams out of the box aoe attacks. with her good heals and team heals when she attacks.
Lumi - great heals and powerful attacks

I take out other teams top damage dealers first unless they have a healer that brings them back to life then I take that healer first. I can usually take one down before they get a taunt or heal off. Chew taunts as fast as he can then heals himself. Rey does massive damage with Leia's crit bonus backed up by Lumi's force blast. Then I take down their attackers one at a time. I find it to be a good combination.

Mol Eliza

Other leaders in the group. Just wondering how my team does when the ai plays them.
Dump truck
Maxooo
Charlatan

Peanut

I wonder if you are in my bracket cuz Mol has like 15 accounts on my server,

Sounds of your line up I'd say it work work attacking but when in D it probably fail hard with 2 easy picks before chewie taunt, well I know my droid layout would hk, ig 88-86 gen soldierpoe
Top line up for GW is say

Job

Thanks for the feedback peanut! I have not put much into droids. I will take a look

shimmy

I'm building a droid/geno team not so much for arena but just because it seems like it'd be neat and gives me something to do. Also building a first order squad and a counter squad.

CantonSam

I found there's 2 pitfalls in your defense mode controlled by AI.

First, AI control Leai to use stealth first and Rey for her special and got foresight instead of offense up.

Second, may be you don't see real DPS that blow out one of your toons easily and doesn't need turns to boot them up like GS, FOTP, IG86 and of course they are faster than chewie and make a one-hit-kill Rey then your team is no longer a beast.

Try understand how's AI think and play, so you will see how to manage your team.