Welcome to GAC! I consider it the most fun game mode.
An important strategy in GAC is reconnaissance. You need to check out your opponent’s roster, and “predict” what they will use on defense, then try and save teams on offense to counter the defense you expect to see. This becomes a little bit more obvious as your roster and GP expand.
For where you are in the game, I might suggest using your Geos on defense and Palp for offense. Geos are VERY tough to beat without a specific counter, and if your opponent doesn’t have it (specifically double-zeta Traya), it is a very solid defensive team. If fact, if your opponent doesn’t have zzTraya with an equivalent gear-level to your Geos, you can probably use them on front-line defense and soften up your back line.
Phoenix should be solid defenders for you for a little bit, I recommend taking out Ezra and using him with offensive Jedi in your case.
If EP is the current team you’re farming, Dooku could be a solid choice but there may be better... who are you currently using on your EP team?