What I have noticed for the girls that go up quickly in our gym its more a matter being able to x well but maybe the hand was facing the wrong way etc. My dd is 10th to death on little things that really do not matter. Her skills however are VERY solid. She scores mostly in the 35s now which is decent but not great. Our HC seems more focused on skills, uptraining etc that they do not spend a huge amount of time on routines. If she was in a gym that did, I have no doubt she would be scoring in the 38s. What has happened is each season is significant polish on old skills and solid work on new ones.In the situation I posted about the kid is 7.
As an aside, I wasn't implying I think fast tracked kids are sloppy. I just don't know enough about the sport to know why kids would be fast tracked.