I don't want to pay a full weekly salary when I'm only able to play 2 games and others are able to play 3 games. That's the more important issue and not fair to those who do only play 2 games this week.
Training skills is a secondary issue that comes from this argument. Yes you can train FT or ST but I'd rather have the option to train something else if others also have that option.
There is a justifiable reason for the salary discount and it makes sense. This should not be changed.