Let me fix this for you: "at best they can prevent the Nazi from threatening, punching or murdering members of minorities, while he's in hospital".
Which is enough for me. The ultimate target of Nazis is to eliminate all non-white, non-Christian people, and every Nazi must be treated accordingly. The world already saw once what happens when you don't prevent Nazis at all costs, we don't need to repeat history.
> If instead the Antifa would attempt to befriend that person and to have good faith dialogues with them, they would at least have the potential to actually reduce racism, and reduce hatred on both sides.
This strategy only works on people not dragged into a fully closed world view composed of conspiracy theories (of the sort of "George Soros fabricated 9/11", Flat Earth and other stuff). Given the immense power of Facebook filter bubbles, where people end up with every post on their timeline being either fake news, propaganda or conspiracy crap, it's next to impossible to counter this. You can't counter 10 hours crap per day on Facebook with maybe a couple hours talking - it might have worked in the past, but no way today.