How far you could or should spread 'em depends on your perspective. There are technical people, and people who wing their own solutions. You have a medical system that in the best cases is very careful about developing drug protocols, and you have recreational drug takers. Both feel there is a truth in how they operate. No one answer. When I miss or overtake a BP pill I am consoled to think for a moment of Keith Richards. Functioning as a machinist, I like precise fits, but I can crank out a solution if I have to. I don't see any reason to design a sloppy solution with great care from the ground up.