Ive been doing orange and purple side of mara for a couple levels on my 5 shaman team and I dont remember any pull that had 8 of anything in it other than the larvae pulls right near noxxion. Unless you are talking about inner mara which I never had much issue with generally even in leather/cloth on my casters (lvl 44) What I usually did was pick targets on each shaman and then cast chain lightning immediately. I then dropped stoneclaw totems and magma totems and by then CL was up again and that was enough to kill almost all of them. Sometimes I would have one death but not very often. 120dmg to a prot paladin seems kind of high, I think they only hit my main shaman for about that much. You are wearing full plate and shield and all that right?

Since I assume you have one enchanter on your team putting things like stamina enchants on things, having a big hp pool certainly helps.