maybe you are getting me wrong:
I actually want pull to be effective on gold/plat and would be glad to hear strategies to make it viable.
(other than with the Acolyte)
Justicar
I picked the Disciple cause it is one of the more non-cheesy Shotguns. Venom or Graal or GPS would of course be much better. Or you can take a pistol with power mod, or Hurricane, or Saber. or whatever rocks your boat.
Strategy - shoot a mook's shields off, apply pull, then reave and move on; reave will finish it off(even on Plat). If your gun is not that strong, apply reave first for some extra damage from warp ammo.
Pull is a reliable quick stagger, especially the area version - it's harder to dodge. It will stagger any mook short of pyro and goon (I'm not sure about the pyro, it might stagger it as well) and will certainly trigger either the flip or the bubble of a phantom. So you stagger them until one has it's shields off, then a quick BE and you start a chain of destruction. For bosses - Reave, Bubble of Love, Reave for double BEs.
Make use of your dodge - it's super fast.
Always keep something reaved for DR.
Anything else is just sensible tactics that apply to any other kit - spawn control, movement, avoid getting surrounded, and so on and so forth.
Acolyte will of course be one of the best guns on her, as it makes any kit with short primer or detonator shine, and killing phantoms is one of the best ways to deplete the wave budget fast. Still, something with high DPS against armor can be just as efficient, seeing as how, especially on Plat, phantoms are not the only thing that force you to respond with high priority.