I would say that nothing really matters before age 13-14, or eighth grade.
I know in the case of my oldest, he grew a lot between 12 and 13 and got much stronger between age 14 and 15. The growth spurt changed the way he approached the game (and not necessarily for the better) and, eventually, the position he played. He was primarily a catcher until age 15, and a pretty good one. But a coach watched him run once and said, 'Son, you're now an outfielder.'
He was an outfielder in high school and is one in college. He was thought of as something of a power hitter in high school, but it's clear that won't be the case in college (for one thing, he's not big enough).
I wish he'd had gotten the chance to play some middle infield (where his size matches up better) and maybe gotten a few innings as a catcher at the high school level. But that's the way it goes.
The bottom line -- let him enjoy the game and just play it. If he shows promise when he's in the eighth grade, meaning he's ready for high school pitching, then perhaps it's time to take things more seriously.
Even then, it might be too early. In the case of my son, he was on track to play hockey in college. ... until his junior year in high school.