While these are interesting anecdotes, and I am certainly not in a good position to criticize (being especially good at procrastination), I wouldn't not put too much weight on these stories. Maybe some of them are more myth than reality, and trying to follow the ideal might do more harm than good?

Certainly it sounds like a good idea to have a strict daily routine, but maybe it doesn't work for everyone. Maybe it didn't even work for most of those interesting people, but some PR person or biographer or whatever deemed it necessary to portray these people's lives as such.