You're trying to make it pure Science. A bowyer knows it's a blend of Art and Science unless you're working with actionwood and Glass/Carbon.
Of course it works differently with various woods but you can still group them closely based on how they react.
I'm surprised you take such umbrage to Steve presenting this theory and with your background wanting a single verdict. After all OJ was guilty, not guilty and innocent all at the same time. Does Philosophy explain that?