Athletics are not fair – I’m roughly the same height as Usain Bolt, but no amount of training and work ethic would have ever made me better than a well below average sprinter. I’m more genetically suited for slightly above rec play pickleball…
I’ve often said that nobody deserves to be HS, college, or pro level athletes – it’s not that that they don’t work incredibly hard, it’s that the cost of admission is unearned in the form of genetic gifts. IMO, “Projectable” is relative to more than height, it’s the perceived gifts that might grow into an advantage as the athlete matures and possibly levels up.
@adbono has some great advice about Trackman data and learning if your sons have attributes that can be leveraged for success. When my son showed up at Arkansas as a junior, he met with the pitching coach regarding his Trackman data and how they were going to leverage his natural pitch movement. He went from a Juco closer/stopper to a Friday night starter (at this point he was also 6’5” and touched 97 – so also projectable).
However, if you want to see an amazing story of a kid who’s 6’ tall that throws in the low 90’s and was the very best player in college baseball in ‘21, look at Kevin Kopps. He was redshirted, troubled by injury, and struggled to get outs in the SEC. He figured out a pitch, a slider or gyro something and nobody could hit it even though they knew it was coming. 33 appearances as a reliever, 12 and 1 record across 90 innings with an ERA of 0.90 and 0.756 WHIP (an amazing young man BTW). This is an extreme case, but the point is you’ve got to have something that brings you success at the next level to compete – being projectable just helps you get the opportunity.