I would try Lumi as your lead until you get QGJ up a star or two. At 4 stars, he's not very viable in Arena until then. Lumi's leader ability will give a little boost to health every turn. Try her with Eeth, Ahsoka, FOTP and 88. Avoid challenging teams with Dooku, as you are Jedi-heavy. If that doesn't work, you could add a healer (JC for FOTP) or a taunt (Chewie for Eeth). You should also pay attention to the team you are challenging. You have a lot of toons that are pretty even strength-wise, which gives you flexibility to craft a team to the circumstances. If going against a team with a taunt, bring in QGJ; droids: Eeth. Pick their biggest threat to you and focus on that toon until dead.