I start with sorcerers galore and just AoE the hell out of everything, then a few druids close by to clump it all up for more efficiency. I stick to mages and druids only until I get Heroes, then I pile up the bottom with heroes for single target damage. When I reach level 41 I start filling in a whole bunch of GMs to kill Ferumbras.
"Dovie'andi se tovya sagain"
Some mornings it's just not worth chewing through the leather straps~