You made some good points.

Compared with our size, humans, I think, are unusually weak. Neanderthals were supposed to be stronger than Cro-Magnons. Maybe our ape ancestors were always a little weaker physically than their ape relatives. Perhaps closer cooperation among our ape ancestors than exists among other apes meant we didn't have to be as strong individually to succeed. Maybe physical strength was not selected for in humans as much as other abilities.

I saw parts of a chimpanzee documentary on TV in which the chimpanzee troops were compared with human gangs that protected their turf by killing isolated enemy chimps near the turf boundaries. The "lazy banana-eater" image did not appear to fit. Perhaps modern human gangs are partly a holdover from our ape ancestors.

On a different point, although some animal mothers and fathers are willing to RISK their lives for their young or their mate, I'm not sure it's clear that animal mothers would choose to die for their offspring if the choice was clearly "my child" or "me".

I was just reminded of the airplane instructions: Put the oxygen mask over your own face before you put it over your child's. Evidently they worry that if you reverse the order you might fail to save either life.