Is there any reason you can't just taunt one when it runs off to healer?
If this is in karazhan I can understand, but otoh if it's in Karazhan you probably won't be getting much use out of thunderclap either.
In situations like Kara where tclap and aoe won't work what I do is the following, assuming I'm MT.
a) Pop Bloodrage.
b) I pull, always. This means I have initial aggro on everything. Pull should happen very shortly after bloodrage, is popped, within 2-3 seconds.
c) Soon as the pull is initiated, target the mob that's CLOSEST to you, among Skull and X. If X is closest to you target X, if skull is closest to you target Skull. Soon as it gets to you Shield Slam it. The mobs hit hard enough that you will easily have enough rage for this. If you get unlucky and dodge/parry the first attack so you don't have enough rage for Shield Slam, hit Revenge if you shield blocked, and Devastate as a last resort.
d) When the other mob gets to you (regardless if it was skull or X), switch target and use whichever is up (Shield Slam if possible, Revenge second priority, and Devastate last).
e) Now just switch back and forth between the targets making Skull slightly more of a priority than X.
Sometimes it gets really tricky in cases where you're pulling in a very tight corridor and you have shackles. There have been times where all 4 mobs are literally right on top of each other to where it looks like one mob. In those cases it's just hard and you gotta do the best you can.
For what it's worth, I don't switch targets with tab because it often gives me targets I don't want. Instead I just left-mouse click the target I want (X or Skull) and then use ability on it.
Edited, Feb 5th 2008 2:58pm by duvar