I'm a long time player, quit once and returned.
I enjoy training the most, that's why I decided to go homegrown.
I have a proposal for training, if stamina decrease will make it difficult to play one trainee for full game: Make a limit for minimum and maximum training, for example, player would need 38 minutes for full training, but will need to play 10 minutes in order to get any training. So in practice, not much changes, but you could still be competitive and train. You would still need to plan a good training schedule, but wouldn't be penalised (by new stamina) if you want to train six or three players.
People who train are the core of this game. Without them, there would be no good players for people who compete without training. Any improvement of training is welcome, but as others already said, don't make it too easy.