When to start gearing a new team?

Ya leave Phoenix alone, as long as you can get thrawn. They're good but not super useful to power past what thrawn requires. Also depends on what you want these teams for, arena? Cuz arena you'll wanna max out your characters, but acquiring squads for TBs are very useful, as well as factions that have exclusive rewards, like nightsisters and others. Basically figure out what their use is, then analayze how high to power them up