The common misconception is that people think Drk/War are better MTs and pld is just an OT when in fact, all 3 tanks are really quite monstrous in the MT role. They all have excessive personal mitigation. Pld actually gains DPS from tanking via shield swipes, has dps gain enmity actions (swipe and scorn) to easily maintain their lead, and shields are awesome passive mit when you are actually being hit. Pld is only OT because its great at MT AND OT while Drk is great at MT and OK at OT. War is great at MT and useless as OT.

Pld isnt the best OT because its a bad MT. Pld is right up there as a MT powerhouse. The only reason its OT is because Drk and War are terrible OTs. Pld can cover, intervention, run to the party and shield them from an AOE with passage (without turning the mob as a MT), has a ranged DPS window to aid in doing far away OT mechanics(Panto 2 comes to mind), and even cure without intteruption in a pinch. Drk can TBN the MT or another party member. War can.....fell cleave? Oh wait they do that as MT. So...war does...nothing as OT. You dont need to be smacked to use SIO.

If all 3 can MT like beasts and pld can MT or OT and bring massive additional tools and value even when not getting hit in the face, its pretty clear who shouldnt be getting hit in the face. But if there were no LB party limitations, Pld/Pld would probably be a competitor for best combo simply because Pld can MT as well as Drk/War and still be useful as OT. Pld/Pld can swap all day and protect each other constantly. War is dead weight if not MT.

The singular exception why pld isnt a good MT is because it's opening pull is junk. But when you have a drk or war, they pull and you just swap after. Except thats bad because then the war/drk is on the sidlines being a blue DPS with a solid MT(pld) instead of a solid MT(war/drk) being supported by the obscene support a pld brings.

You loose value having Pld Mt, but not because pld is a bad MT, but because War/Drk are abysmally bad at being an OT.