I drove as healer for years. Starting in Wrath if I'm remembering right.

The things you need to think about are just different. Now I would say the best part about hunters in this scenario for PvE is misdirect makes tanking a lot easier. Misdirect + a blood DK makes driving as a healer real easy.

When I drove from the tank I noticed I really wasn't ready for it. I was constantly loosing my healer and found managing ranged was a bit more complicated. As a healer I can easily keep ranged in front of me and remote move them like chess pieces on the battlefield. All in real time while healing. Doable. Not really doable for me driving as tank because driving as tank meant I was doing a lot of noise input. Like jumping around and re-positioning for no benefit.

Driving as healer means some tank encounters might smash you. Like fights where tank movement is critical to success. I always found those harder. Like Serpentrix. For those the best strategy might be to drive from the tank. I never really found a workable solution on those it was all just luck or bad luck or destroying keys.