As a Main tank myself I pull according to my healer and dependent on the mobs being dealt with. There are some rather massive mobs in this game that if you get more then a few of them it's hard keep them in check as their always bumping with other mobs. Not allowing them to get in a easily controllable mob. Then there are the ones that do a large AOE that force you to have to reposition every time. If the healer is comfortable with large mob pulls then I'll grab then in large chunks. But I do so in moderation and make sure that they can be positioned best. I notice at times smaller mobs are easierto DPS down faster, especially when you have the right composition of DPS. Larger mobs is a pain for DPS that currently do not have that good of AOEs. In the end each player has their preference and when using the DF or roullette, each person has equal right to how they play because it is a random set-up.