Thats what I do.

I always drive from the tank. I tend to position healer and dps where i want them with a stop follow command, for me this in "3" which is bound to move backwards on the slaves.

I then run the tank around gathering big groups, try to make them bigger each time. Then on my tank I have the videofx screen for the priest / healer heals.

I have tried driving from priest / healer before but i find multi boxing a healer tank combo, it more important to be a better tank than healer.

Jim.