Both EX fights are not extremely strict on dps, they do have dps checks but they are not packed on top of each other.
What this means is, that everyone should be able to place their highest burst during those checks on the target where the dmg needs to go to.

On Bismark you want everyone to pop all their cooldowns when you go on his back for the first time and dps him hard (make sure people are actually on top of his back otherwise that attacks don't count).
Then once the dragons come out those will last long enough for everyone to have most of their buffs be up and able to be used before the dragons actually have to be dead.
These are the only two real dps checks on Bismark, obviously you ll still need to be smart about dpsing the birdmen adds down in a timely matter and only getting on Bismarks back when you don't have the debuff anymore and have cooldowns up.

Ravana has the same kind of dps checks, only time the check is real is during the butterflies if you can kill all the butterflies in time, the rest of the fight is not as tight on enforcing high dps bursts.

As for WM, if you had a good pre 3.0 rotation, there's not a moment during those fights when WM is needed and most likely not a moment where it is actually a dps gain over a good old rotation.