>>122039women are biologically fat. they're supposed to have more fat than men, usually for child-rearing reasons like fat deposition in breasts and rears, metabolism being slower, energy more likely to be stored as fat, etc. - hence why the comparison between fat men vs fat women in your case is slightly biased. i feel like most women should know this by now, its always been a topic of discussion in the fitness community.
yes, the reason you see more "fat women with regular sized men" is because they're supposed to be fat. even if they weighed the same kg/lbs as men, the woman would have more fat & the man would have the most muscles. unless its a super skinny man vs a mid-sized woman, which wasn't at all what you described. i also feel like people of both genders put a bigger emphasis on determining a woman's weight than a man's. people are always so much concerned about a woman's measurements. maybe its a psychological bias paired with biology.