Why do players get fatigued so easily? I have the training plan on 21 hrs, I have a fairly heavy rotation (meaning I have a lot of starting caliber players that I play in different formations, rather than 1 set of 11 on 11) and every game there's like 20 men fatigued? why?

sounds weird, heavy fatigue is usually only caused by overtraining. Maybe you forgot to click save on your training schedule?

I have the training on 22 and it is saved, and every time a game goes by, even with the gameplan set to balanced between starters and backups, like 10 men are fatigued all the time.

This training this is weird now