Realpsojed: Sounds like you two need to start using combat tactics. Angles with a bow and spells. Narrow points with melee.
This,
running around corners and just wait at edge hugging the wall, that gives you time to kill the first mob that comes around. Other mobs have to go around the first mob which gives you time to kill the first 1v1. And then the next ond so on, just make sure you dont run into an unexplored room
Also works wonders with rogues and mages versus succubus, their bloodtsars will hit the wall while you can shoot them freely.
Use doorways to bodyblock, so only one mob at a time can enter. Of course doesnt work in level 13+
Stone curse best spell you can have to minimize the number of fighting enemies.