Looking at what you have going on I'd say that zetaing Maul and switching to Sith would be your best bet for climbing in arena with who you have.
I'd use: Zaul (l), Vader, Palps, Dooku, Nihilus.
If their gear was higher, I'd recommend any of your other Sith over Vader, Palps. and Dooku (I'd replace them in that order) Assassin, Savage and Sith Trooper are your best replacements there.
Yes the Zaul meta is over, but he is still really good in arena. Better than Wiggs or Zader or Jedi. I'd be amazed if you couldn't break top 200 under his lead ESPECIALLY with CLS on the board. He's all about TM gain and Counter attack. AoE Daze is a pretty good answer to that.
Before the CLS meta, I did see a few Wedge leads in high end arena, but they all had Chirrut and Baze in them as well. Most of them had R2, a few had Lando or Jyn Erso. If you have CLS that opens up more rebels to arena viability, but most of them aren't that great without him.
Finally, whatever team you end up running, (other than a Nihilus lead) you really need to make sure your damage dealers have both a crit damage set and a crit damage triangle. Characters just don't hit hard enough to make it to the top of arena without that. You don't have crit damage on Wedge currently, and that cripples his effectiveness. I see you have a crit damage set on Leia, but a crit chance triangle. That is better, but she is really wanting the crit damage triangle as well.