As far as ZF goes I wanted to point out that I did this on a prot-specced paladin in shockadin gear. With my consecrations ticking for around 200 instead of a mere 95 that it ticks for in my actual tanking gear I tore the mobs health down very quickly and healing totems did very little to heal them. Also finding good places to LoS the casters you can contiunally move the casters away from totems if you need. It was never once a problem for me. You wouldn't even need an actualy shockadin set as a decent healing set should have enough spell dmg on it to do just fine. After my shockadin set began to break I started to switch it out with my healing set and it wasn't a problem either.