I've been running FO in arena for a year and a half now and break top 50 in an old shard filled with revans and trayas
You want ZZKRU, Executioner, FOO, ZFOST or Kylo Ren (Depends if you need more tankiness or more TM gain, beside, Kylo is good to pop Jedis foresight) and Thrawn.
Thrawn is mandatory to suppress Yoda/Sion/JTR, but if you want full FO you'll go for both Kylo and FOST.
Pump up your FOO speed, Marching order into FOST, FOST taunt giving tm to the whole team and from there you can stun (KRU), Fracture and get your team going.
Note that against palp lead team at equal mods you'll loose most of the time, target jedis, nightsisters, JTR and rebels without chewie.