Need zeta advice

Padme team is a must eventually, but a zeta on Brood Alpha my give you a more immediate boost.

I use CLS in Arena too and the only time I ever lose to a defending JKR team is if buff imm doesn't stick on GK, though I can usually still pull out a win. If you're struggling on offense vs JKR and you're following the right kill order with CLS, RHan, Chewie, R2, and 3P0, you probably just need to increase R2's speed. That said, I definitely wouldn't advise on either of the last two zetas for the team. They're certainly not bad, but Raging Wookie is rather limited in use nowadays since he shouldn't get his CDs increased due to being stealthed versus either Traya or JKR. Similarly, 3P0's other zeta, assuming you zeta'ed his mass assist, doesn't provide a whole lot, although the immediate max health on R2 can still be useful in shorter battles like arena if you're using him as a sacrifice vs either Revan team.

I would think either using it on GBA's unique or a Padme team zeta would be your best bet. Probably leaning towards GBA since it looks like your Geos are more developed than your GR.