I've never been in a fight per say but i have been bullied and even as an 11 year old fighting a taller opponent, i was able to grab him by the shirt and use my weight against him. I grabbed his shirt and spun around in a circle using both of our momentum to swing him around till i let go and he was forced to stumble into a direction a few feet. I never punched though or did actual fighting stance type stuff.
I've since then learned that putting your weight and rotation into punches helps A LOT. I've done tests on regular punches with just my arm strength on boxes and then actually threw my body into it and rotated and shit and it does go much faster and with more force.
I'm 5'6 and 329 pounds so i might be short but i'm definitely not some stick that can be picked up or tossed around.