I think it's a worthwhile schemata to look into, and I have no issue at all with OT/MT's having two distinct roles, rotations, and supporting abilities, doubly so if we can fit them onto each singular tank.
The only reason that the DPS MT could exist is that the design allowed it to exist. You wouldn't "stay in DPS stance" if you end up in the floor two autos later.
Hey man. I feel for that.
Hence why I said our "current version".
I think the worst I've said of the Heavensward stat situation is that it was a false choice, but conceptually, giving up 25% of your defense for +25% damage is fine. It's a stance swap where you can't change it during a fight.
That's the crux of the issue. Tanks are not weak right now. They're the most bloated they've ever been - It's just not in their beat stick. Relative corrective adjustments are fine. The Ranged are looking to receive one fairly soon, it looks like, so a corresponding one for the tanks and potentially healers would be appropriate.
The kind of sweeping boost that is being asked for requires trimming the fat by a proportional amount, or you're just going to get monkey pawed again.