The most interesting data on archery and penetration can be found in the reports of Dr Ashby at Tradgang.
penetration on bone

One of his updates is about single and double bevelled broadhead. The single bevelled BH are more spinning and impacts on water buffalo shoulder bones clearly show that the bone is more split by a more spinning (single bevelled) BH that by the usual double bevelled BHs.
Consequently having the BH spin is a premium.

Moreover the weakest part of an arrow is the junction of the BH and the shaft, the insert. I wonder if sophisticated ethics insert aren't likely to be more breakable?