it can work well like that but be aware of the limitations. Your healer will be the group leader and therefore running ahead of the group. This means it's your healer who is likely to pull aggro - not a great situation and a point in favour of a pally. I've not tried the priest+4lock method so can't comment on that, but my plan is to have a pally tank out in front of the 4 shamans so he attracts the mob and the shamans can heal him if needed.

I have all my paladin keys unbound so i can mouse click on what i want him to do, while the shammies are all controlled using keynindings.