You’re making some incorrect assumptions. Why do you find it impossible that you can be more productive with 5x6 than 5x8 because you’re more well rested? If y

You’re making some incorrect assumptions. Why do you find it impossible that you can be more productive with 5x6 than 5x8 because you’re more well rested? If you do 10 work units per hour at 5x6, and you do 6 work units per hour at 5x8 because you're worn out, then 5x6 is more productive. Your mistake is thinking that the first 6 hours of 5x6 and 5x8 are equally productive. Maybe that’s true. Maybe it isn’t. But to claim that it definitely is and anyone who thinks otherwise doesn’t have common sense is just silly. Edit: to further clarify, are you claiming that 5x10 is definitely more productive than 5x8? What about 5x16? What about 5x24. Or 7x24? Your confidence that you’re definitely right that 5x8 is better than 5x6 makes me wonder where you know the ideal line is and how you know that.