I have always struggled with coaches only training up to 5 senior players at a time. This should be reviewed and in my opinion increased to 6 at a time. Perhaps have assistant coaches with a cheaper salary (half of normal coach) that you can hire to help train a specific skill and allow 6 players to train in one skill at once.
Option 1: Senior coach train up to 4 or 5 players at a time and if hire assistant coach then up to 6 players can be trained at a time per skill.
Option 2: Allow floating assistant coaches (2 or 3 MUST be hired) to go around to various skills each day allowing up to 6 players to be trained per skill.
I feel this would help with the problem many complain about... the training progress players make in the needed/important skills is too slow.