I did Baelsar's Wall today while leveling my DRK and farming tomes for the anima, and also had a SAM run ahead at least once and then come sprinting back with a bunch of mobs. They always seemed to want to be ahead of me, so I stopped at the bottom of the big set of stairs and they just kept running up. I knew a group would aggro them at the bend and they did. I said "don't do that", waited a second for them to get pretty hurt (the healer was my partner), and then saved them. They ran ahead again after that, but didn't go too far this time.

If DPS want to pull without an agreement from you, the tank, they need to learn from their mistakes. They do it because they assume you'll save them. Don't. There's no wrong way to pull anything outside of extreme/savage/ultimate content. Do whatever you want. If they want the tank to do something different, they can queue as one.