Gear merely sets the cieling for how well you can do. Skill determines whether or not you're living up to it.
Let me illustrate this for a moment: If I stand there as a Monk and do my 1-2-3 of my damage skills - not even my buff/debuff/DoT skills, I would do a certain value of damage. By comparison, actually performing my full rotation, using cooldowns, etc. tends to about double that value. However, I have run into people in similar gear who do half that original value. I have run into people who do similar damage to if I was to just stand there and auto-attack something.
Especially now with more complicated rotations and cooldowns to use, gear matters less and less to DPS compared to raw skill.
As for "how do I find good Bismarck EX DPS?" Make connections. Talk to people. Keep trying. It's one of the rare cases in the game where, for once, the onus is on the DPS to perform. A lot don't know how to handle that.