Don't be so sure, from what I've learned, it takes multiple gunshots just to fend off enraged rottweilers, let alone kill them. My fists, or yours, would likely do nothing whatsoever.
I could be wrong. However, it can take multiple gunshot wounds to kill people as well. With smashing the windpipe, I wasn't think of a fist per se, but of a grab and twist. It's a little hard to explain.... this comes from my stepdad who has raised many GSDs, and who has never had a problem being recognized as the alpha by nearly any dog he's met. As he explains, with his own dogs - every day he shows them who's alpha. I don't think fists are effective on dogs that are hell-bent on a fight. However, knowledge of weak spots is key.