Thats what i do now.

Ill set up my Shaman like so,


s.......s
...E...
s...p...s
at the top of the entrace to his room

That way eck is also always getting hit by concecration and i dont have to run to use shield of righteousness.
I kill him very easily, unlike when i first tried and stacked my shamans on top of each other

Edit: Formatting sucks :P