I would say I am an average to below average tank as I hate their play style in this game. When I do play a tank in a roulette at a higher level, I pull 2-3 groups of trash at a time and still manage to do alright. I probably take more damage than I should, but oh well.

I find it hard to believe a tank can't do large pulls, unless as others have mentioned that they are a brand new tank, or if they are under geared for the content. Outside of those two reasons, a tank should at the very least attempt to do large pulls if they are asked to do so by the party.