It's worth plenty!
Of course I'd be silly to claim that I know definitively how Karma works. There are no fixed rules for how to behave. The exact right thing to do in one situation may indeed be to collapse an opponent's wind pipe in a life-ending act of violence. Death is a release, after all, and everybody must exit somehow. Maybe to the onlooker a murder is a murder when really it was a loving agreement made prior among soul friends. Specific situations and all.
But in general...
My own training exposed me to some practical Buddhist philosophies. The concept which struck me very deeply was the whole, "Live by the Sword, die by the Sword -over many lifetimes" idea. One fellow student described a friend of his who I had met and who was beaten badly shortly thereafter during the execution of some criminal activity; he was a guy who had visited violence upon others more than once in the same world he moved in. It was an up-close example of the principle and it left an impact upon me. The cycle of violence is a learning mill of an extreme sort, and sometimes it plays out month to month. I have no doubt it extends over lifetimes.
I suspect that's probably got more to do with killing for food than killing in anger/fear. -Also recall that the C's once dissuaded against the idea of killing even a grey alien, -and those things don't even have their own souls.
I've had my share of hard challenges, but I've gone through them in relative luxury. -Being born in a safe country, having a good, healthy body, avoiding all manner of natural disaster, being surrounded by supportive, powerful, successful people... If I accept that there is such a thing as Karma, and I absolutely do, then I must also conclude that I've been doing something for a while which leads to these sorts of non-violent experiences. I shudder to think how many stupid, violent things I've done and had done to me in order to learn to stop Punching It Forward. I'm not going back to that, thanks. (I just wish I'd come to this realization at a younger age, because I was a bit of a jerk back then.)
The other thing I learned through martial arts was that the best way to win a fight was to avoid being in one in the first place. -And that wasn't said in the commonly heard consolation prize, virtue-signaling T-Shirt sort of way it is often said. It was meant in absolute earnest and I live by it. And it works. There are plenty of ways to win in life (and against dangerous opponents) which don't come down to crushing a person's face with a blunt object or blasting a hole in their chest with a hand gun.
To re-quote Ursus-Minor:
Life is Religion.
But life is also Kung Fu.