That help on paper, in the reality you have the delay for the new petrification to appear, the time it take a boss to move, the fact that the other tank may have gotten out of taunt range while giving room to the melees and then mines are on your way, etc etc that can and will put you in the 80-0-80 situation, if you are not fast enough for these liitle things that add. Shit happens, beware of it. It's why this is a bit harder than it looks the first time you do it.