I guess I'm just way too underleveled. I've already used the supply cache and am on the second wave there. None of my party members have enough strength to sustain the fighting until they come in and surround me, and I don't have very much health either. It's not a situation where I can simply "have one person turn the screw while all the others taunt" because there's like 9 enemies on screen at once, and each one of them also takes roughly 1/2 my HP.
Keep on mind the new waves of enemies spawn at certain points of your aiming 'progress'. Meaning, if you keep turning the screw while fighting the enemies you are effectively making it much harder for yourself. This is why you are facing these 9 enemies at once -- try instead to clear the area, then turn the screw a bit, stop when you get message about reinforcements (it should be 5 enemies or so) kill these, then rinse, repeat.
As a bonus doing it in this manner will let you save between the waves, as you'll get out of combat once the field is clear.
Also, leaving the Templar Knights free to roam can make it much harder as they'll turn regular Templars into Horrors which can quickly murder your party with their ranged area attacks. Either sleep the knights or focus them first, if you can't do either keep eye on them and interrupt them or take out their target they try to convert.