Arame:
The higher your body fat percentage is, the higher the probability of your testosterone levels dropping and turning into estrogen. Like ole boy said, that’s why chubby girls will develop parts quicker than skinny girls during puberty. Also that why you’ll notice that fat men who live sedentary lifestyles tend to have more passive personalities. Also you’ll noticed a lot of feminine gay guys tend to be on the thicker side or straight up fat.
Who are these men you've met?
Estrogen doesn't make you a passive person. Spend any time in nerd spaces. Those are some of the most aggressive men sometimes - especially the fat ones.
Also, there are plenty of feminine gay men who are twinks. Bears and cubs are usually pretty masculine.
Meanwhile, I have run into scores of muscular, high-testosterone men who are total pushovers. Yeah, testosterone can make people aggressive, but it's more about mentality and worldview.