I am one of those WF casters who don't like to wait on clerics and prefer to figure out way to do quest without them.
Kinda working on strategy of Invaders before presenting it to the pugs group. Main idea is to use beholders in there for
good purpose. So instead of healing tanks it's could be better just to heal Beholder who is main weapon in there. ( like Deathstar from Starwars). So if you see LFM looking for beholder healer plz dont' freak out . You can see video below for idea in general ( not the best but still gives general information). I am personally don't like tanks who see beholder and trying to kill as fast as possible. They can be usefull pets if you use them right way.
http://www.youtube.com/watch?v=PCH99tjpigE