What I was eluding to formula......is the phenomenon where your arrow is not flying true.....but still hitting where you're looking. It could cause a loss of KE at the POI.....even though your arrow was flying exactly like your FP.
THAT is why I say that "some" shoot mechanicals as a "band-aid" to mask tuning issues. Not all.....by ANY stretch.....but with a mech......KE is so much more important.
That's all.
You are indeed correct, sir, and I agree with your analysis. I was simply aluding to the fact that the poorly tuned bow that some use is the issue, not the choice of head per se. I have found though some heads are rather pesky to get right though.
I'd be willing to bet you can shoot several different heads with good accuracy from your bow, indicating a good tune. BTW, good hunting this year!!