I am not sure if this has been mentioned before, but I always thought it would be good if when you added your previous managers experience, it could also manufacture a playing career for you based on your selection.
It could be an option to do this manually, select the clubs your manager has played for including career apps, and goals or the game could automatically create the career, based on factors such as place of birth, favourite team(s), nationality and 'past playing experience'
So for example you could have a Dutch manager with International (Global Level) experience, born in