Fenwaysouth,
I think you're exactly right.
On many youth and high school teams, the ace is more effective when tired and sore than the next best pitcher is when well rested.
The baseball field is not a lab and never will be. However, having some sort of starting point for saying, "Ok, maybe the big guy needs a break," can help a lot.
And if a coach also starts a season knowing that a pitcher has additional risk factors identified by ASMI, such as not taking a season off for conditioning, doing showcases, and throwing curveballs before age 14, the coach can know to be a little extra careful with the one factor he can measure during the season.
By the way, the injury prevention value of knowing a player's personal history is one reason I recommend finding ONE travel coach you trust and sticking with him. Accumulating a closet full of uniforms from various and sundry short-term and cameo team affiliations, especially joining a team just for one big tournament, is just asking to be "rode hard and put up wet."