I would have told you to start with Ghost, Phantom II, both TIEs, and Biggs with Ahsoka, Fives, and Wedge on the bench. Definitely wouldn't tell you to run Clone Sergeant in your fleet. He's got a target lock, but he's really slow and it has a low proc rate. In reality, his best use is as a tank. That, however, requires Plo and Mace both to be effective, and your Plo is too weak to really be viable.
You are really close to having a full Republic fleet, but you really need Rex for it to work. There are a number of other really good comps that you are close to, but they require TIE Advanced or Scimitar.
So the comp I listed looks like it would be most effective for you out of what you have in my opinion, but your fleet really needs some rare ships (only farmable from hard nodes, cantina nodes, or Fleet store) in order for it have a shot at the top top of fleet arena.
