I also don't know the numbers. Once I heard that all of the three tanks lose something like ~35% of their DPS if they stay the entire fight in Tank Stance. But it doesn't matter to our discussion because there is no need to stay in tank stance the entire fight. We were talking about situations in which a tank may want to go to defensive stance to use some extra mitigation and avoid a wipe. In this scenario the stance dance that WAR has is better than the DRK's which is better than PLD's.