Why assume if you choke him out, that he is not carrying a knife. It quickly comes out as you apply the choke and does damage to the choker. They teach that in knife class. Probably in prison too.
My point is that if you are in the mix, it escalates. The woman could easily start stabbing the good samaritan wrestler.
Guns gave us distance benefits. You don't want to physically engage unless you really, really have to. Romanticizing one's physical abilities is dangerous.
Whether you should intervene is another complex story. We've done that endlessly.