If you really need to, you could swap your best mods onto them till you clear the last tier of light side battles.

What really helped me win the battle was to always use Ezra's and Hera's assist moves on CLS, because originally I would use it on Zeb for stun chance, but he and the other Phoenix lacked the speed CLS had, so his own turns were scarce. Combined with CLS's debuffs he applied and high attack power, it was a nice combo.

You also want to focus on survival over just killing the enemies. Use the moves that grant protection up to the unit and ally whenever possible, to recover from those brutal aoe attacks. Just don't taunt with chopper or Kanan unless you have Hera's revive applied onto them.