Stamina has its uses and can aid in running up-tempo offenses and keep performance up during the game. However, giving up valuable training time if you have trainees worth training is a waste to some degree. Also, excessive stamina can screw up your rotations and minutes for maintaining game shape. Personally, I think you can train stamina 2 weeks in a season to include All-Star week and one of the playoff weeks if you need stamina.