There are plenty of boys out there born after 9/1/2000 who are 5' 10" and taller. Keep telling your kids everyone else is cheating - in my son's middle school there are plenty of big boys. Ever watch a Florida middle school team on youtube? much better than St. A's Freshmen - not a lot of holdbacks in our schools either
Take a look at this article if you don't think Southerners are naturally bigger and more athletic - just wait until the SEC states start laxing more - Carolina isn't even the true south