I would raise the point that as was raised in the house, if the concern with murder be that someone's life is being ended one must note that many of these crimes could lead to the same result.
An example comes to mind from the movie Dirty Dozen where Charles Bronson explains that the reason he is locked up because he shot a man who panicked and ran off with all the spare ammunition in a fire fight.
In a combat situation, most all of these cause the death of one's comrades.
I am not exactly in a position to research this, but isn't it often the case that accessory is charged the same when it comes to murder in a criminal sense?
Ftr I don't even support the death penalty for murder, but small steps...
I don't support it except for serial murder/rape and of course treason.
For the military it has long been established that the military carries with a need for a certain level of discipline otherwise it can become very dangerous, especially dangerous for a democracy.
There is then beyond the harm that many of these above actions can cause including death on a mass scale. I am not saying it would be appropriate sentence in every case of a guard falling asleep, but there are situations where I think it is the appropriate punishment.