Dropping Chewie, replace with ?

Xorthyx

I was thinking possibly Phasma to add more AOE or Dooku already being 4* the counter is pretty mean. What toon would you guys add? I am mostly a f2p so somthing I can farm would be best. I almost have sid to 7* so my arena shipments will be open, my main 4 are,
6* Sid
5* Boba
4* JC
4* Lum

The 5th doesn't have to be someone I have but here is what I've got,
6* Chewie
4* Talia
4* Opressor
4* Dooku
4* Old Daka
3* Phasma
3* Resistance trooper
and some other low stars