It looks like the devs are also working on the pros and cons of leadership in the game.
How about including underway training. The player would have option of training crew (a clickable option while on patrol or training cruise).
Example, Torpedo loading. With each exercise or number of exercises, crew gets better (faster).
The penalty, fatigue factor increases.
Diving, start with relatively slow dive times, with each dive the time becomes faster until reaching fastest possible time.
Torpedo training of weapons officer using neutrals or friendlies as target
Gunnery practice
Damage control drills
Overdoing it, should have a penalty, like morale dropping.
When done right , morale and efficiency improves
Some could be automatic. Let's say that when assuming command with a fresh crew, Alarm diving time on a VII is 60 seconds. With each dive, the time becomes one second shorter, with a maximum of five dives a day.
If exceeding the daily maximum the dive times remains the same as before and cmorale drops.Thus, it would take about 5 days to bring the crew to an acceptable standard of efficiency. A realistic time.
But, since the human factor is involved, maybe not all training is succesful and it could take longer (random or other factors can be tossed in)
This could be an optional realism setting.