correct, more stars = low training, and if you win a level and player loose the star, again goes a little bit faster.
thats the .1

.2
scout is like a player of, 4,5 stars, but, trained.
so, he can be good, or bad playing in the same % as all players of, 2,3,4,5 stars.
To have reference of who's better training, look his wage, his salary, and look his value. Young players fast trainers have the value 30,40 times his wage. Old players of near 30years, and not good trainers have the value near x10 times the wage.
So use this information to compare between 2 players.