Look at this from the perspective of the group, not the individual. Diversity pays, big time. A group that has gargantuan hunks as well as skinny little folk will win through over a more a less mixed group. I have seen this in caving, where you need both - it all depends on the situation and the circumstances.

I have really seen this in SAR. Our best teams were a mix of youthful enthusiasm and knowing elders, male and female. Pair the microbiologist and the plumber - between them they will have the right stuff (that is not a hypothetical pairing, by the way). Be sure you have a good technical climber and someone really good at EMS. Everybody pulls together.

Survival is much easier in a team. Sometimes you can really cold and lonely if you are by yourself at 3 AM.