If You Were A Class/Job Designer...

[Ultimatecalibur]

Me? I wouldn't change the tanks very much. I'd introduce 2 new dps jobs.

New DpS 1 (Samurai?) would apply its own non-stacking version of the Storm's Eye/Dancing Edge debuff with its primary damage combo and a version of Storm's Path (that doesn't stack with the Warrior's) with a tertiary combo.

New DpS 2 (Red Mage?) would apply its own non-stacking version of the Rage of Halone debuff with its primary combo.

These new jobs should shift the tanking meta so that Drk/Pld/"Sam" = War/Pld/Mnk = War/Drk/RdM.

[Sousoulsu]

Me? I wouldn't change the tanks very much. I'd introduce 2 new dps jobs.

New DpS 1 (Samurai?) would apply its own non-stacking version of the Storm's Eye/Dancing Edge debuff with its primary damage combo and a version of Storm's Path (that doesn't stack with the Warrior's) with a tertiary combo.

New DpS 2 (Red Mage?) would apply its own non-stacking version of the Rage of Halone debuff with its primary combo.

These new jobs should shift the tanking meta so that Drk/Pld/"Sam" = War/Pld/Mnk = War/Drk/RdM.

I like this a lot, especially promoting the PLD/DRK combo. As is, it's too big of a loss.
Debuff balance is important.