I agree with Habs ^. I'm going threw on impossible right now and I've only been using the plasma cutter. So long as you aim for limbs it works wonders. It'll work even better for you if you aim for the same side of the body (Example: Take off both the arm and leg on the left side of the body and they will die).
Death Smiles At Us All, The Only Thing We Can Do Is
Smile Fight Back