I say that's not bad for Sullivan. He's a good penalty killer. He was hired more for his offensive numbers, but I wouldn't call him a slouch defensively. Of course, this is all in context... I wouldn't put him higher than Legwand defensively so I assume Legwand has a 90 or so defensive rating (I haven't checked the link...)
But I would most certainly not put him at a 90 in durability. That's smoking crack right there.
(edit after reading the chart)
I take it back. Crazy stupid rankings. Completely random does not really begin to give it justice.