And yet, from the beginning of time we have stories of people who used that erroneous assumption to avoid detection/identification.

Take a random group of people such as a Live Television Audience, have them all put on gray sweats in their size. Hood up or down by choice. Have your local cop arrange them in order from most feminine to most masculine, first facing away (as in pursuit) and then face front.

You're gonna have a few truly surprising outliers and a lot of pissed-off people in the middle areas but not where they want.

That's why you used the cop. Everyone hates them already and can restore their own feelings by disregarding their opinions.