Are DK, DT and ShT arena viable for long?

DT is too good, and while tarkin has tm removal and good debuffs, he’s not able to do even close to the amount that DT can do. DT is quite possibly the single best character in the game. He has both cooldown increase and a permakill like Nihilus, but he also has a daze on his basic, TM manipulation with krennic, can inflict heal immunity and has an area dispel (rare in the game)and has a multiattack against rebels (arguably the strongest faction). He has a partner that is insanely good. Alongside krennic, he deals increased damage, can protect him from crits and heal and i almost forgot, he has a guaranteed crit. It’d be hard to argue taking him out of any empire lineup. Oh and he gives troopers health steal so ShT gets a boost to his health just by being on his team.