Or how about two guys of the same weight but one is heavily muscled?
Two guys the same age have to do the same amount of pushups, situps and have the same amount of time allowed for the run on a PT test no matter how they are built. Women can pass physical fitness tests doing half the pushups, less sit ups and running much slower than a guy the same age. For example a 17 - 21 year old male needs to do 42 pushups to pass, a 17 - 21 year old female needs to do 19. The standards for women are a lot lower than for men.
“do they make allowances for guys who weigh differently? A 120 lb guy should carry the same as a 220 lb guy, right?”
It would be called ‘weight neutral’ standards.
How come time doesn’t enter into the equation? Like one soldier carries 70lbs 5 miles, and takes two hours. Another carries 100lbs and takes three hours. This would be ‘time neutral.’