I can't answer what you are asking but I figured that I would throw a few points into here as well.
Yes, the player role makes a difference in training from what I understand. However, team tactics play a bigger role if I understand correctly.
In terms of the growth of individual skill, it has been changed as well on a player by player basis. As a result, not all players will grow the same rate for every skill. In the prior version of the game, there was little difference in the growth rate between players as a result. On top of that, not all players have a skill cap of 99 for every skill anymore. The combination of the two made it pretty impossible to distinguish elite players from the rest in the past iteration of the game.
That said I think it is more than safe to say that we are all still learning the details of the "new" development system.
- Paul T likes this