It is easy to figure out that in the highest divisions of the best 2019 and 2020 tournaments there will be kids that are the physical equivalent of high schoolers. If the 2020 kid is 6 feet and 175 lbs it doesn't matter if it is because he is a holdback or because he matured early. The people running your club have an obligation to make sure that their teams are entered into appropriate divisions or tournaments. Any AA division means the kids will be physically mature.