Didn't read the entire thread, but IME you shouldn't shoot any animal head on.
I've arrowed my share of whitetails, with recurves and compounds...and I have killed a few with head on shots, but they were from the ground and not from an elevated stand.
If I hadn't had a dog, I would have lost 1 of those deer.
Problem #1- If the animal is looking at you he can react to the shot (ie duck, move). I understand some bows today are like rifles but all he has to do is move a few inches and you have problems.
Problem#2- If you attempt that shot from an elevated stand, you are almost guaranteed to [bleep] it up. I've had to track too many that boneheads shot, not realizing that from an elevated stand, the vitals are covered by the head and neck. They aim for the brisket and end up wounding the animal or sticking a shoulder.
The worst was a 160 class buck that a fella I was guiding got excited about and drew on too early. Instead of listening to me, he let one go and ran it thru the left shoulder.
We found that buck dead 3 days later in a pond...
