For TB and tw defense purposes, the best Phoenix squad doesn't actually use Ezra. He works best with Bastila Jedi anyway though.
Using hera/sabine/zeb/kanan/chopper gives them a lot more durability, since Kanan and chopper uniques both give health recovery ( chopper at the start of a turn and Kanan on suffering a debuffed) and zeb gives prot recovery. They are also less vulnerable to bad RNG causing you to lose Hera, Sabine, or zeb when a taunt isn't up. Chopper has a dispel special like Ezra, except his also removes 10% TM per buff dispelled from the entire enemy squad, and also has a 30% assist chance with possible CD reduction. Kanan and chopper get the foresight from kanan's zeta special, which feeds tons of TM to everyone. Sabine's aoe also can't be countered, which will minimize those horrible assist chains in TB.
The AI sucks at playing Ezra with Phoenix, so for defense its best to leave him out provided the rest are up to par and zetad.