As someone who's DD has been mainly in gymnastics in the midwest, I find these observations interesting. There is one MW junior elite we are keeping an eye on - Norah Flatley, who was at a non-powerhouse gym in WI until about 3 years ago, and then she went to Chows to finish up her JO career and move on to elite.
She is the perfect Olympic age - 16 in '16. I would imagine for her to get to the point where she is today, she's had to train the crazy hours and crazy skills over the last couple of years. But before then, I think she had a saner beginning and it seems to me she may been able to peak more gradually to get to where she is today. I guess I'm not sure about all this and someone might correct me and say her progression is on the same warp sped of others on the junior scene today and has been intense since she was bitty, but it I think it may have been more gradual.
From what I can tell she was a L10 in '12, and qualified elite in '13. I don't know if you can go elite much later than that and make the '16 team.