Inappropriate Development During Training

[Balon11]

While training, I prefer to assign defensive drills to my goalkeepers so as my defensive players. But, I've observed my GKs tend to gain much more aggressive ability than other defensive players despite that defensive players need aggressivity more than goalkeepers. This causes an uneven distribution. Is this an error of the game, or I'm doing something wrong?

[Der_Ryan_M]

Then your GK is younger or has lower skills in the drill you train.

[Kwal]

Your players probably train more skills on that specific training, whilest your goalkeeper might only train 1, aggression in this case.
Your players could gain the same experience (depending on age, tier, average drill %), but your field players could divide that experience over like 4 skills and your goalkeeper just on 1.