For managers who train in a monoskilled way this will have 0 impact. If they training an outside player, insted of having IS 2 or 3, they will have it in 3 or 4.
But when you train real SF's you can train in 1 season 3 different types of training. That's training your player in most of his skills, so it's false that i'm going to have 1 skill(with luck) from cross training.
Just an example, my SF is close to pop in;
JS
OD
ID
SB
IS
With crossed training i would get at least 4 skills up.
Now it's on 40k, but when he will be a 80k SF, ofc i won't be happy that he increases 1 level of RE or whatever skill he had high.
You understand now, that bad managers who train monoskilled players won't have any problems, but managers who care on training, will be affected by this bad system?