FO Full Zeta Squad -- Who/When to replace?

Foo cannot be replaced in any fo squad really. Marching orders is just too strong.

FOX replacing FOTP perhaps. Kylo is a freight train so I'd keep him in, and FOX has stacking max health so throw a full set of critical chance mods on him with a critical chance holo-array.

Replace FOTP with FOX and you have the best possible line up for FO atm, but wait for at least G11 to put in FOX as he will not have enough survivability and will deal less dmg than FOTP

Fotp is very very squishy, and will easily be focus killed on defense. My preferred all FO squad is definitely krum/kylo/foo/fox/fost. The AI is very bad at handling fotp/fosftp on defense, although on offense I would probably drop old kylo for FOSF once he's g11 at at least.

Another vote for FOX to replace FOTP.

At least for arena.

I've had significantly more success with FOX instead.

Ditto. Fox replaces fotp. Also there are some good hybrid squads you can use to beat nightmare teams in arena. The lineup is kru, Fox, foo, rhan, thrawn. Stun vader with rhan, cast marching orders on fox and either use fox to dispel their tank if their tank has pretaunt or hit palp if not, kru stuns thrawn, thrawn fractures sion, then kill palp and Nihilus. Your kru with +30 speed from his leader ability must be faster than your opponents thrawn or your thrawn has to be faster than your opponents thrawn. If your kru is slower than your opponents thrawn but your thrawn is faster than your opponents, you can fracture thrawn and stun sion instead. Not as good though. If you face a team without a pretaunt it’s super easy. Fox does enough damage to palpatinne (and removes his tm) so that palp either dies or he’s forced to use his heal instead of stun.

Whatever you do though don’t leave the hybrid squad in on defense. It’s a purely offensive squad and will drop like a rock on defense.

Im not saying you should replace FOTP entirely rather mix match teams that suit the current opposition, neither characters are bad but each is used for a different situation, FOTP excels in single target destruction while FOX is good for cleaning up weaker characters and removing turn meter, a lot of people say he is squishy but isnt that where FOST and KRU comes in? To soak up all the damage? Ive had the pleasure of getting to use both together and let me tell you, they absolutely can destroy powerful teams

FOST/krum double tank with ogkylo and FOX is a TM machine (not up to zzEP level, but still excellent). KRUM will pass out advantage every time he's damaged, and spamming ogkylo's aoe will give 50% TM to everyone with advantage, while possibly resetting his CD's at the same time. FOST's zeta will spread ten down, healing immunity, DoT, and stack FOX's Max health ( from his unique) at a very fast pace, along with the TM to the assisting toons ( from KRUM lead ). It all stacks up really fast with krum/kylo/fox/fost. The 5th should be either FOO or FOSF ideally, since fotp is just too damn squishy. Fox will build up his health quickly enough that he isn't squishy for long, and you can actually afford to use a health primary on his circle, triangle, and cross, instead of a CC triangle or offense because of his unique boosting his offense based on his Max health. Crit chance isn't really needed with him, since he will almost always have advantage and his basic always scores a crit against debuffed enemies.

https://swgoh.gg/u/brakir/collection/?f=first-order

For DSTB, I always use krum/kylo/fox/foo/fost and haven't dropped any waves with them yet.
For tw, I use them on defense running krum/fost/fox/kylo/zarris. It sounds strange to use her, but that squad has insane Regen capability against everything except top meta teams, and the abilities are so well idiot-proof that the AI won't screw it up like it will if you use fotp/foo/fosf as the 5th. They haven't been taken 1:1 yet since I finished taking them to g12.

Thanks all! I'll drop FOX in my arena in place of FOTP and see how it goes.

It's been said, but I'll say it once more to add legitimacy. FOE > FOTP.

Once FOE is G12, the gear you can stick on him makes him a monster. I am suddenly in contention for top 50 in arena in a Dec. '15 shard with him. Could almost never break 100 with zFOTP.