yeah they're ridiculous. I just struck with a poison weapon, then retreated into that hole area where they can't each you. let the poison run its course, then ran back out there, poisoned em real quick again, ran back, etc. pain in the butt
but yeah in amana I wound up just rolling through the missiles rather than blocking them. additionally, there's that one spot that's just ludicrous to beat conventionally, so hug the left wall and make your way to the cave, then come back out from the cave and start slicing. you'll get 'em from behind, and you're closer to a wall cover if you need to retreat.