Why can you assume that a good player is also a good coach? I mean most coaches in football(soccer) were not great players and are way better at coaching than their players.
Are good tabletennis players good coaches because the sport heavily relies on an analytic mind? Or is it enough to have been taught to be a top 4 player of the world that you can teach it to others as well like in the old times where a master of his trade will learn his student to become a master as well?
You raise a very good point.
This is what makes table tennis so difficult and so special. It is a football match with your tacticians
It is your "speed chess" with decisions required to be made in a split second
It is your racket sport - where whole body movement, technique, endurance etc comes into play
For one to make it to the top level as a player - requires one to master all of the above.
For one to become a world champion from China, requires to go through a good 20+ years of hardship and defeats the odds with the amount of pressure and discipline from a huge pool of competitors and political challenges.
It is not uncommon that Chinese players require to make more sacrifices to succeed than oppose to other countries.
As the Chinese playing and coaching cycle being very "young"
player retire at 30, coaches retire at 40 odd
This has been the current formula of making sure that the coaching staff is young and up to date with the game itself.
The rules are forever changing, and with 40+ we have already seen a different preparation in training methodology and I gather it is because there is young coaches who are driving the change, than compared to your older coaches which could be more "traditional"
My answer to your question, is 99% of the time, this formula will work.
Whats nice in CNT part is that it is not 1 coach, but rather a whole team of coaching staff and sport sciences, medial team, trainers etc so this is why CNT is so strong. It is not a one man show