To answer the question ...
Tomorrow's club coaches are (in essence) being "groomed" by the succession of club, academy, high school and college coaches they play for from the ages of 6-22. Not saying that's good or bad ... just reality.
Very few coaches AT ANY LEVEL AND IN ANY SPORT possess a "total package" of people skills, teaching capacity, demonstrator capacity and playing experience.
The best coaches are like the best players: They work tirelessly, AND have the ability to evaluate themselves (and others) realistically, identify their strengths and weaknesses, work and play well with others, accept well-intended criticism, and lead by example.
You don't learn these things from a book, or a coaching course -- although those methods MAY have value in certain technical and strategic areas. You learn them from the array of parents, teachers and coaches who have set the bar high through their own commitment and performance in WHATEVER IT IS THEY DO.
As to the CESA situation ...
Inheriting a presumed stacked hand from a successful and well-liked coach is, in many ways, more problematic than building from the ground up. By age 16-17, top-level kids SHOULD possess the understanding and discipline required to police their own effort and performance.
Why?
Because, if they intend to continue in the sport, they will likely play/train for a succession of coaches, NONE of whom will be uniformly capable or popular.