Yeah I just let people who grief die on PLD and WAR, then do my pulls as normal. I do wall-to-wall pulls already, if I hold back 1 GCD it's because I had not actually hit the entire group. I do this for a reason. All they do is make it slower by dragging mobs away from me that then take longer to pick up due to the slow GCD compared to other games + an extra GCD to take things off them. It's different if they intentionally bring mobs, but this happens less often than you think, most of the time they just run into a pack, decide "here" is a good place to stand, then AoE and wonder why the tank is elsewhere picking up the 3 other mobs they didn't collect that then ran off to the healer, and now the tank used their extra gapcloser, cannot gapclose to the melee who ran in, and now has to walk over. Annoying as hell when people do that without at least talking about it first so the tank knows to expect it and can plan ability CDs around it so the pulls never have to slow down because AoEs only hit some of the mobs instead of all of them.
I usually explain it first though. Granted, with sprout-healers I always ask then whether they want wall-to-wall or single pack, and I respect their choice. And I hope DPS in groups can respect that choice, too. Everyone was a sprout once.
If someone get rage-y after that, salt-stocks-are-on-the-rise macro the first time, vote kick the second.