My very recent ancestors ate an awful lot of cheese doodle equivalents, but I can't say they thrived on them.

You probably did state yourself clearly, I just had time to be a fussbudget, Monday is part of my weekend. I do think it's a useful line of conjecture, don't know if outside of extremes--some groups that for longer time spans ate little or no carbs, some that ate what we would call very low protein--there's going to be that strong a variation from population to population. Some groups did eat omega six fat levels comparable to what we eat today--if it was found that they had some adaptation to omega 6 related metabolism, that would be interesting, if excess omega 6 was generally hazardous to humans, you'd expect some sort of adaptation in groups that have been exposed long enough.