I think Thrawn can replace TFP in your squad. He is more durable an his Fracture cant be resited.
He is viable at 5* and G10/11.
Mod him for Speed so that you can go first in Arena and give him the Zeta for Ebb and Flow (makes him slow when someone is fractured). Don't waste Potency Mods on him. All of his Debuffs cant be resisted and there is no need of Potency for him. Try to push his Protection as high as posible (Cross and Circle Mod) and make sure his counters make some Damage (Crit Damage/Damage on Triangle).