what're you talking about? There's not been a clear of TOP yet.
/s

WAR and PLD just don't offer damage compared to GNB/DRK, especially a DRK/GNB pairing. And until players that're going to get through it get more familiar and accustomed to the fight, wanting to maximize damage to get through DPS checks would matter more than a little bit of survivability IMO. This isnt like Savage prog where that extra mit can help push through deaths. Unless the veil/shake support can let a healer get away with less GCD healing / healing resources being spent and instead go into more damage spells, there's really no difference whether it's there or not if a single death is a wipe regardless of what tank kits are brought into the fight.