I don't think SE wants tanks to have their dps stance damage at the same time as having the tank stance boost to enmity and defense.
I wouldn't particularly mind myself, but it would require additional changes. PLD oath gauge is gained differently depending on which oath we have active. Dark Knight has some abilities that are only active, or work differently, depending on if Grit/Darkside or both are activated. I'm not sure about warriors but I think they have changes too between stances.
So they could in theory strip away tank stances and say give tanks a passive trait that boost their defense and their enmity at all times, but it would requite more work tweaking the tanks, war and drk especially, without it. And then there's the question of damage. Do you let them keep the damage they get from dps stances? Because the whole point of these stances is to nerf their dps and buff defenses/enmity when tanking, so if you let them keep the damage with no tradeoff, the question is does that make tankes too powerful, having so much defense and keeping their dps stance dps? Or do you lock their dps at tank stance levels and make solo play more frustrating?
IMO, I'd rather they either increase boss damage output so that tanks need to consistently be in defensive stance rather than just needing it for an early enmity lead, or just leave it as is, than have their damage nerfed locked in for solo content.
