Training def, mid, att ?

[k1tb]

Is it worth training defenders, midfielders and attackers separately?
If my bonuses are 10%...
At the moment I use this kind of training:

This will give me max bonuses, but also all the players will have the same training...( defenders, midfielders and attackers, also GK )
( Should I mix up individual training for def, mid and attackers? Is it worth it? )