Have you figured out what happens if you train any given player with a highly mixed routine, like, say, Set-Piece Delivery? Though it's listed under Attack, it has two skills for forwards, two for defenseman and one for goalkeepers. Say, you train a GK with this set. Is the game engine going to say: "I'm rolling the dice on the skill: Crossing. I'm rolling the dice on the amount: 1%. Who's raining? GK? Sorry, doesn't apply, come again."
Or is it more like: "Rolling the dice on the amount: 1%. Rolling the dice on the skill... Wait, no need, since the only applicable skill is Rushing Out. Here's your 1% for Rushing Out."?