Rather than naive, principled. I know that people can change and I know that it is not likely that they will. I don’t agree with mowing people down. Did you watch the video in this thread that Papa Bear posted? It was of police work done appropriately in South America, two cops and a dude with a knife you could really see in the video. Much more threatening. But the cops were athletic, active, smart and fought the guy, disarmed him, cuffed him and called the medics. That’s what should have happened here. Suggest you watch it to see what I have in mind.
As someone who was “cut” in the line of duty, until you are faced with it you will never know how fast it happens. Anyone within 21 feet or so of you with a knife can close that distance and cut you before you can draw your baton, taser, pepper spray, or weapon. In that circumstance you draw the weapon that will provide the most efficient stopping power and allow a better chance of survival after initial contact if they cross the distance and make first contact. Even then from within 21 feet they might still get you before they go down.