I've given this previous thought. In the last 30 years I can only really think of Morrison whom has forged out a career outside the lower leagues after being released having 'graduated' from our youth team. 99/100, clubs get it right but there will always be the odd one which slips through the net, develops rapidly further down the line, and ends up generating a big transfer fee.
Luke Chambers
Ivan Toney
Mark Bunn
Bradley Johnson
Michael Jacobs
All done alright, and probably quite a few others who should have kicked on, but never did?
In response to your post though, I think league status is key, so any sign of danger sees us revert to " experienced heads" every time?