A careful read of the article indicates its from the perspective of maximization of lifespan and maximization of short term productivity. Why must they both be the same or have anything to do with each other, beyond numerological coincidence?

You're talking about a completely different metric, which is quality of life.

From personal experience in .mil my "combat effectiveness" for uncle sam probably was maximized by only being able to sleep for about three hours per night. I would not wish that hell on anyone.

There should be more to life than merely making someone else richer at the fastest rate you're capable of, or being the last guy in your cohort to die, while suffering in agony.