PLD gets the job done, but it's in no way optimal for any speedrun period. The lack of AoE damage really kills any hopes of that.
DRK is the better tank because it has more cooldown usage (Dark Dance is 60s while Bulwark is 180s. Just an example), and it just outright deals more tanking damage. WAR is just outright better in every conceivable way. The only argument you could make is Hallowed Ground being the better cheese button.