Penetration on a live animal will be greatly effected by the sharpness of the blade. Cut on Impact heads are sharp to the tip. Chisel point tips depend on tearing until the blades reach the hide. An extremely sharp cut on impact head will lose very little energy getting through the hide and flesh. When encountering bone, it' s possible the chisel point would then work better. It may be better at breaking bone (just a guess).

Study Dr. Ashby' s evidence and see if you agree.