warriors are better flag carriers imo , they have more mobility than pallys and do more damage thanks to bladestorm doing 240% weapon damage . there`s no role that a warrior cant perform better than a pally atm. blood dks are still kings in pvp tanking , they are in another league
I'm not sure how recently you came back, but currently tanks do very low damage with no vengeance and there's no vengeance in PvP. I don't see either warrior or prot pvp as being a viable PvP spec. You might want to compare Ret and Arms instead.
I really wanted Prot PvP to be viable and soldiered on (only ever casually) even after the removal of vengeance in PvP. But the rescaling of damage in MoP to nerf zero vengeance tank dps was the nail in the coffin for me. On the plus side, Ret's survivability is better than I recall before MoP and the spec "feels" more flowing and fun now imo (Holy Power generation is more generous).
warriors are superior to all other flag carriers. when a prot warrior pops all his cooldowns, he will be immortal forever to then have so much mobility that allows them to move across the battlefield without any problems not to forget the mobility also adds to your survival.
imo, dk aren't as god mode as they used to be and they are a LOT easier to kill then druids and monks. prot pala is bottom om the barrel. all the others FCs outdo prot pala on survival cooldowns + mobility or selfhealing. last and not least, none of the big pala cooldowns can be used on the FC. This means no bubble and no Hand of Protection, not to forget Lay on Hands is not uasble in rated pvp(arena and rbg).
if you want to play a prot spec when doing rated pvp, your warrior will be the way to go.
ps. forgot to mention prot warriors got biggest AoE damage ability in the game. Bladestorm for prot gets 240% weapon damage instead of 120%.