If you'd like to do some testing, feel free to add me on steam and we can try it in some custom games. http://steamcommunity.com/id/asamu_
I don't think monster mash is at all a problem for HE with the right build. Rev crystal healing is slow, and while Kroq-gar with healing can fight the nobles if he's not getting debuffed, he can't avoid them while netted in place by Teclis.
As for dealing with the priest, the archers can focus fire it whenever it comes into range, or they can skip a noble and go with a flying lord instead, as I outlined in the post.