You need to account for genetic outliers.

IIRC, Jocko Willink believes that his ability to function on little sleep is genetic, he just doesn't need much of it.

He has mentioned that this was a running joke in the Seal teams, which presumably consist of people already selected for their ability to function on little sleep, not your average "7 - 8 hours of sleep" folks.

But then normal people who need an average amount of sleep start "getting after it" by waking up at 4.30 AM because that's what Jocko does.

You can wake up at 4.30 AM as a normal person, but you'd need to go to sleep at 8.30 PM - 9.30 PM for that to be sustainable.

You can't "discipline equals freedom" yourself into optimal performance under perpetual sleep deprivation.