That's something that's very plausible. As a kid, I remember that in every team in our league, the pitchers played many positions, mostly in the infield, and they were the best athletes on each team's roster and that was on every level. I don't know how really that has changed since then (still almost 20 years ago) but I think that as much as you have to take precautions at an early level with a pitcher's arm, you also need to test his durability and increase it as the pitcher gets older. Pitchers also need to be wiser I think. It seems like most are looking to throw those fastball heaters but yet, a good slider, changeup or curveball will be weapons of massive destruction if you can master them early, thus, preserving your arm for a longer period of time.