looking for advice regarding long term strategy

Phoenix will always be needed. They will help both arena and fleet.
I would focus on one team at a time. I got mine to average meaning 7*, g8, ab mats 5 before I moved on to another. I got a workable team of Phoenix, edi, ewok sith and fo. Then I built them higher. I do that for each team. I focused on toons that were both crew and in that team. Helped me to stay high in both arenas