I think that SE thinks about TANK a sort of meat shield. I mean in other games concepts the tank is the defensive one oriented with shields high def etc. But here in ffxiv its not like this as u can all see. The Warrior its in fact a dps but with a high capacity to absorb dmg. His skills are all offensive with high dmg output Too. So the thing is that For SE the tank its a sort of damage absorbing Class but not a defensive only oriented. So i think its a very Great idea to put dark Knight as a tank.