Well, I got annoyed enough to make a weak aura that tells you what is petrifying and what it needs to be tanked with. Still working on it, feedback would be appreciated. I have not tested in 25m yet. It will say "X Guardian is Petrifying, Tank X Guardian next to Y Guardian".
10/31 Edit: Seems there was an issue here with text truncating, so instead of the group of 4 auras, I'm posting them individually:
Just use the New->Import feature from WeakAuras and copy paste. Only 1 of these will be active at a time depending on which boss is petrifying.