I think that even if you could somehow factor out all the imbalance that presently exists in stance swapping, it still represents a gameplay/control issue. Why on earth would you deliberately make a job's gameplay more awkward?

Stances in this game need to be better implemented, around the board.

WAR and PLD have no benefit to being stanceless, in this expansion. If you accidentally deactivate your stances, you lose all of your gauge. So why does the game let you do this? This doesn't represent a "challenge" or something clever that you have to work around. It's just inefficient design. You should have an active stance by design from the time that you activate your job crystal until the time that you remove it.

Why do you have two separate hotbar buttons on PLD to swap between two stances? In the lead-in to Stormblood, we were told hotbar space was at a premium, which is why so many actions were removed. But shouldn't your first thought be to merge down the stance buttons? If you have n mutually exclusive stances, you only need n-1 hotbar buttons to swap between them.

Implementing 3 or more mutually exclusive stances (like on MNK) works on the same principle. Press a button to swap, your previous stance icon goes to the hotbar slot that you just pressed and replaces the icon for your present stance.

On a job like DRK, where you are required to deactivate Grit or Darkside in order to swap states, the deactivation process does not function like a true oGCD and 'sticks'. But this is also easily solvable. Create two separate actions for each. One 'on', and one 'off'. Let them share the same hotbar slot, and change out one for the other when you swap.

In the long term, I'd like to see 'Stances' implemented as their own unique action property which address and standardise the above problems, in place of being implemented as 'Spells' or 'Abilities'.

If you want to differentiate between 'job identities' in the stances, you just need to change the costs of swapping. And if resource costs aren't your thing, an alternate approach could be to take a recast penalty to your offensive cooldowns whenever you swap. Either way, decide if swapping should be free or if it should have costs and just be consistent.

I think the biggest obstacles to improving tank gameplay for all players are fear and selfishness. You don't need to hoard advantages over other jobs in order to stay relevant. You shouldn't feel that your job needs to have a 500-600 dps advantage to stay competitive with the other tanks (and if you did, you really should have more pride in yourself than that).

It also relates to the health of the game. You want people to tank? Fix these gameplay issues. Make stance dancing fluid, regardless of the tank that you pick. Not all of us want to play Warcraft-themed axe-wielding barbarians. There are plenty of ways to give the tanks unique aesthetics without deliberately sabotaging our gameplay.