I explained to you in great detail in this thread why you will die to these mobs as an Impale DH. In that thread I showed the maths behind why your DH would need over 1 billion HP per reflected dagger in order to survive. Now factor in that you’re throwing three knives per cast, and you’re doing a few attacks per second.
If you keep dying to them, it’s not only expected but entirely your own fault.
Skip them.