Maybe it sounds fine to you, but to me, a night owl, it sounds absolutely insane. I would go insane if I had to do this and I don't know if I would ever recover.
It *is* insane to wake up at 4am if you go to bed anytime after 10PM.
I know some people will swear before god that they can function on little sleep, but the fact is that your decision making and judgement is seriously hampered by maintaining a long term sleep deficit.
That could be a plausible explanation by Holmes' defence for all her actions that got her in trouble in the first place! Personally, I find my own coworkers who lay claim to having such regiments are usually the smallest contributors in the team and mostly 'talk' too much and do too little.