In my later games I started using traps (big style), on the shriek bridge pile a load of traps behind you just before you get to the middle and then you'll only have to fight the ones that come at you from the other side.
My personal 'unfair moment' was when I was battling the gatekeeper and his pals in the ruins and for some reason all of the werewolves and shadow wolves from the side alcoves also decided to join in (i think there's about 15 of them in total including the gatekeeper's gang), this has happened to me only once but I was very lucky to survive.
The funny thing is it never happened to me before either until after I read your post. I had Shale, however, and had the stoneheart mode switched on. He didn't do much damage of course, but stone roar, bellow, taunt and regenerating burst seemed to work wonders on werewolves and shadowwolves. Between him doing that and PC mage using sleep and waking nightmare, they were either too busy being stunned or trying to attack Shale. And the two melee rogues, Zevran and Lel, had a field day. Apart from Shale drinking quite a lot of health potions, there were no casualties. No one got overwhelmed.