Tarkin in Arena? Probably not.

The thing is, all abilities come into this game with counters. Ahsoka needs buffs to be effective. B2 is going to wipe those buffs and make everyone buff immune. TFP or Boba is going to ability block your cleanser. If you happen to be running three cleansers with Ahsoka, either your dropped your other attacker (Nihilus) or Baze (Tank). In either event, your team hits like a wet noodle, or you can't keep your two attackers alive.

In a five vs five man battle, there will always be holes. Too much "meta" and not enough room on the team. Triple cleanse doesn't have any room to switch up the roster without sacrificing some effectiveness to gain an advantage in any other area. I expect we will see the same old teams even after Ahsokas release, or slightly altered, equally beatable alternatives.