Emotionally I understand your viewpoint, if someone has the same maturity, psychologically-emotionally then this gets tricky.
However by nature of that age, purely because one IS that age, you cannot have the life experiences of the ~elder~ <wg> classmates. Those experiences, having been through the challenges the heartbreaks, the failures, (and yes I choose the negative aspects for a reason) which growing older provides... that is the person who you want to have with these skills and abilities.
I don't want a 6,8,10,15 year old child to have those kinds of experiences. Perhaps its unfair or naive but it is my belief. They are children, not little adults, not yet anyway. I frankly do not want young children seriously considering matters in the ways which adults do, they are not adults YET.
Though unpopular, I question aloud the wisdom of having such ranking. It is avoidable, and IMHV (Fwiw) much like avoiding places which could/will be trouble, and I contend it is wiser to avoid situatins where anyone might remotely confuse the issue as to whether, a child is capable of representation of the foundational skills, views and philosophies an art. Be that with words, explaining in detail the what and why THEY practice, what their art is ABOUT to someone who knows (or misunderstands) little
is a skill which is required. Children cannot, because of their age.
Like many "rites of passage" children and teenagers will experience, this is one I contend is unwise to offer. Just as it could been seen as "unfair" that kids must wait to be able to learn to drive at a certain age, this too could well be equally "unfair" <gentle shrug>.
Its my opinion, happy to defend it... or explain it more clearly, if desired...