The SMN should definitely be higher up there. Should pretty much neck and neck with the Monk.

In my group I'm the only person using poison pots. I always save them for when I have Contagion up again (which I have constantly on CD)

And both are hitting relatively the same DPS despite one having a stronger weapon? Something is definitely wrong there, Weapon damage is a HUGE factor for our DPS. The fight is a giant training dummy that fights back so you should have everybody go out to a training dummy and see what's wrong and keep practicing. practice always makes perfect. And as other people mentioned make sure everybody has the accuracy they need