It's situational. A4 runs I've seen PLD struggle on the last phase. When I tank it's like... No damage when discord and ray hits due to being magic damage. I think essentially you'll want a physical tank and magic tank in raid. Sure a PLD can do it no doubt, they just have a harder time. Physical fights they are King, magical fights you want a DRK. As for WAR... I dunno DPS? Lol