Standup. My bad, I took the word of someone else that your son played JV. However, I have never heard of any of those other teams you mentioned. Maybe others have. My son has been involved in the travel/tournament scene for 5 years now - he is also a Junior and I have yet to come across any of those teams in any USSSA, Triple Crown, PG, WWBA or any other tournament. Not saying they are not good, just not familiar. I am also not sure about the Legion stuff. I understand Legion ball is big in some parts of the country, but not where I am from.
The problem comes down to comparing apples to oranges. I really think the only way to truly compare is to get him in a PG showcase and let him get graded. That will stack up his skill set against other kids of all talent levels across the country. Not just the Midwest or just the southeast or just California.
If your son has top level talent, he will make it to the next level. Just keep him in front of those who make the decisions. Individual Showcases, showcase tournaments (Jupiter was a good decision), college camps, anything that you would expect coaches and scouts to be at. He doesn't have to be better than the best kid in the country. Just good enough that a next level team will think he can contribute to their program.
I really do wish you the best of luck.