Why does Clemency get interrupted? And why does Sword/Shield Oath reset combo?

[Shurrikhan]

The ease of Defiance/Deliverance stance swapping is the irregularity not the intended norm.

Given that we have PLD at one end (2 GCDs, highest mana cost), Warrior at the other (no GCD loss, possible health loss and slower eHP increase), and DRK exactly in the middle of that 'ease of swapping' spectrum (1 GCD loss, moderate mana cost)... it seems kind of hard to say definitively that this was never intended...

It also seems hard for them to have actually completely neglected a simple consideration like "If the next 2 GCDs' worth of damage are less than 20% of the total undiminished damage of the swap window, it is better to swap than stay." That's just common sense. I can see that they may have intentionally made that compromise a gameplay component for PLD, but for them to have never considered that their scalar and its offset might eventually intersect (at 4-5 GCDs depending on prior combo position and oGCDs ready) seems unlikely.

And I never understood why Sword/Shield Oath resets combo progression. I feel as though that would help boost PLD's overall DPS/raid performance in end-game, if we were able to switch between stances. Perhaps not so freely.

For example:
(1) Switching to Shield Oath would reset combos, but switching to Sword Oath would not.

Just an idea. It'd be nice to (2) tack on Goring Blade without the damage reduction by Shield Oath, without having to do the entire combo for it in Sword Oath.

That said, this much is (1) DRK (drops combo on applying Grit, not upon dropping Grit) and (2) just dropping Shield Oath early, finishing combo, and then putting up Sword Oath (before having lost a second opportunity to buff your AA). For a GB, that just saved you 100 to 108 potency. If you you could swap into Sword Oath without losing combo, then you could slap on another 50 or 100 during that GB GCD's AA(s).