I didn't confuse them, but for hypothetical purposes would you agree the survival advantage would exist for the human that could chase a deer for hours until it collapsed from exhaustion as opposed to a human who crapped out after a few minutes and died of hunger?
Yes.
But I think you might still be missing the big picture.
The runner with perfect leg structure will survive longer because:
A. he won’t develop chronic pain and joint problems and will need less recuperation time.
B. he won’t burn as many calories because he will be able to run with less effort, therefore he can get by on less food and thus fewer deer
Not being able to catch the deer isn’t really an issue, imo, because...even more important than man’s superior foot is man’s superior brain. he will get a deer if he wants one. One way or another. It’s more about how much prep time and strategic planning invested beforehand, and what he’s got left in him after the deer is caught that can be utilized for other endeavors.