a good leader exhausts all effort and sacrifices themselves before having to sacrifice others

Never served in the military, have you?

The officers do not sacrifice themselves, leaving the men with no one to lead them. (Men = old-fashioned term for all enlisted personnel)

And they do not sacrifice their men recklessly or lightly, but only accept (with a heavy heart and much regret, if they're an officer of integrity like my father was) the absolute smallest number of casualties they can possibly make happen, as a necessary cost to win the battle and the war