They should take away the national flag if the original drafter and/or trainers quit. never FA players from teams closed by staff. If they cracked down on this...there would be WAY less high IS guards out there to begin with. Sure yo ucan get a salary efficient player IF you trained IS...but while that guard is playing C...you probalby lose a lot of games. Same for bigs getting OD/PA/HA...this is actually the same/thing/problem....bigs can get this secondaries for no cost of salary, but SB that adds defence always would add salary. Easy to ahve these bigs if you didn't play them in PG yourself.
You are never fare with NT managers and their work.
The u21 coach and his staff with the senior NT help went trough the 300+ leagues in spain, scouting all high salary draftees and high potential draftees, offering advice for training or for selling. Lots of players are lost due to managers going bot, but some are saved by suggesting inconsistent managers to sell and get the money.
In that scenario with your suggestion all that work is for nothing.
Also very good draftees can go both to managers that are going to play a lot and want to compete or to managers who are not really into the game. It is our work to motivate them, give them a reason to stay with that new excellent draftee or just trainee they bought. But that can only work for a while and in the end the manager will leave the game, but those 3 or 4 seasons you extended the managers life and thus saving the trainee and making it an interesting player that will of course go as a free agent.
Also that work would be lost with your suggestion.