You’re conflating the two. Antifa aren’t a paramilitary. At best they are armed with bullhorns and shields, in terms of protests, but recently we see antifascists taking up arms to protect attendees at drag events from fascist counter protesters.
The SA (Stormtroopers) in Germany were Nazi-affiliated and a paramilitary group. There were a few far-right paramilitary organizations that supported the Nazis and assaulted and killed communists.
Vehemently anti-capitalist would refer to Antifa, not Nazis. Nazis claimed to be against capitalism and communism, but in reality, those paramilitaries I just described defended institutions like the Kaiserreich and fought on behalf of capitalists and burghers. Hitler’s administration collaborated with capitalists, even in America. Their platform stopped short of endorsing worker cooperation, and only wanted national ethnic solidarity. They also wanted to maintain private property, unlike actual socialists.
The tactics you use alone do not make you a Nazi or a communist. It would be stupid to suggest an antifascist is a Nazi because they doxed a white nationalist or made them afraid to organize. That’s literally what should happen.