Help training

Hi all,

I play since long time
For defensive players I do defense's training and for offensive players I do offense's training.
But I just see, some players earn so few points with training it's difficult to earn 1star with green pack.
I test to do offense's training for defensive players and I see that player earn a lot of points... it's normal ?? it's great to earn stars with green pack but for quality during a match it's not a problem ?? if my defensive players develop a lot offensive's skill maybe he will be less good during match , no ?

Thanks you