please, Saori Kimura at 18 was no where near the 24 Saori Kimura. Koga was great in 2015 and then collapsed in 2016.
Yes you want kids to learn earlier, but some people don’t develop as a player as fast as we would like. Plus some parents want their kids to go to college as Japan is really quirky (in general) about going to college later versus with your age…
The ideal situation for a players is to get in with veterans, so that they are a piece but maybe not the important one. PFU with their roster moves is basically perfect for Valdes. She is scoring but has good veterans around her to learn from.
I wouldn't say there's a fixed age per se no matter the country or culture. When you have it --- you have it and there always be coaches who will make sure to see it through even if they go through those bad days.
Valdes is doing well because of the team dynamics since majority of PFU other than Nabeya and Nanami Wasai (who has always been terrible btw) are mostly rookies. But I wonder if she'd be just as effective of an attacker if she played in Toyota with KRob to learn from?