Phoenix zeta order?

I went pretty heavy into Phoenix when LSTB first released, and I still use them pretty extensively. They are my go-to squad for the p6 rebel mission, so I can save CLS and Zolo for the special mission.
They get dropped on defense for TW.
They actually beat the mythic tier of Military Might easier than cls/zolo/chaze/random 5th.
They have two of the best ships in the game imo, and easily the best reinforcement ability on phantom.

For the record, I have g12 zKanan, zZeb, zEzra, and Chopper, and g11 Sabine & Hera. I'll be adding Sabine and Hera zetas shortly and taking them to g12 also.

You pretty much have the correct zeta order already imo. Kanan, Sabine, Zeb, Ezra, Hera would be my recommended order unless you are using Ezra with Jedi.
Hera's zeta seems very weak, but when it is used properly with zeb it adds a ton of DPS to your squad. Use Zeb's staggering sweep, which will give him 50% TM w/ 5 Phoenix +20% from lead for an almost immediate turn. Use his basic to stun that toon, then call him to assist with hera's special and he will daze or stun another enemy and gain 50% TM for another almost immediate turn where you can use his Sweep again. I have had crits with Zeb's special for upwards of 60k damage against buffed, non-debuffed enemies ( the ideal target for his special).
With Sabine's zeta dishing out stagger and exposes everywhere ( both of which allow a stun with Zeb's basic) , Zeb's TM train can very quickly shut down a large number of enemies, which is ideal for TB or assault battles.

For pure utility in a Phoenix squad your order is best. However, I'd be tempted to zeta Ezra earlier because of his extra use in a Bastila Jedi squad, where he's the main DPS.

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.

Phoenix are great attacking CLS teams in TW. I’ve never lost against them and CLS is usually everywhere on defense.

There is a world of difference between a non-zeta, g11 Phoenix that most would use in p5 TB or early on in arena, and a full zeta g12 Phoenix. Zeb and Sabine are completely transformed. I've had zeb one-shot more toons than I can count, and Sabine increases the whole squads damage output drastically from exposes and CC/CD up buffs while also stripping tons of TM from stagger. It's not unusual to start a wave and have all 5 toons go before the enemy even gets a single turn, just from kanan's foresights expiring at the previous wave's end.

For tw defense, they also force the attacking enemy to go in with a very high damage, fast squad; otherwise, Phoenix just keep healing over and over. You can't lowball them and expect a victory.

A g12 Zeb can one-shot a full health Baze with Sweep.