In terms of gear, your dps check more than meets the mark. For example, for my alt group, our two bards both do not have plus one nor ilvl90 gear and our monk has no ilvl90 pieces at all, yet we clear the dreadnought without about 1-2 seconds to spare before phase four.

Not trying to be mean, but I think your dps need to reevaluate their rotations because the gear is beyond adequate to clear T4. Maybe tweek or take out some macros, maybe get some cross class skills they don't have yet, etc, etc.