Giving both tanks an instant ability that does 300 potency damage after parrying would help make parry more useful for tanks again. Of course, they should lower the default parry chance and make parry from gear have bigger returns.

For second abilities, Paladin could use use something to add to their AoE damage. To make Paladin more involved like Warrior, they could add a new combo finisher that gives a buff for 10 or so seconds that makes Flash deal damage.
Warrior could use some ability to gain a little TP back or a cooldown that halves TP cost for 15 seconds or so.