I'ts not bad, you could train the same amount of players as now, same training system, just you could set 3 different training plans for your players.
I choose 3 players to train, one play 48+ on C and I set him to train ID.
The other played 48+ min on PG and I set him to train OD.
The third one played 48+ on PF and I set him to train RB.
Wouldn't that be amazing? Why should we always train the same skill for all 3 players.
Example:
I have one player in the team who has enough passing, the other 2 need at least 4 skills on it.
Now I am forced to train him too, or not to train him at all while training passing for the other 2 players, because I can train just 1 skill at the time, that's not good
This is where we hold them!