I'm increasingly convinced that (for end game arena) cantina shipment heroes are underwhelming compared to GW and arena shipment heroes. That said, I'm not sure where I want to go going forward. Here's what I've done so far with arena shipments, my current team, and my options:
Bought daka and boba fett & have boba halfway to 5*
Current team Sid, lumi, JC, Luke, poogle.
Keep working on boba & hope that at 6* he realizes his potential.
Work on daka (but I'm already pretty invested in JC & like him, and obviously daka isn't replacing lumi)
Work on Poe
Buy some of the cheaper heroes just to work on achievements