I have never felt the need to concern myself if my arrows are strong enough to kill a deer. If I hit him good he dies. Perhaps this is an issue with some of the bigger, tougher, and more dangerous animals, but mostly, the average guy needs to concentrate on tuning. There once was a time when I wish I needed to worry about shaft toughness, footing, etc. to ensure proper performance on tough game, but at age 70, that is no longer a factor. For us guys that shoot wood, we have ash, hickory, bamboo when we are concerned about arrow strength.
Still, if some solid data is clarified, I will be interested in hearing about it.