I don't really care for, or about Wiki - there isn't a single primary source that would indicate - not even to mention proof, that Hitler was ever a member or in alliance with a socialist party.
Many parties at the time incorporated the term worker or social into their party name - in order to recruit nationalists or national motivated people away from socialist and communist parties.
Hitler was know for hating and detesting the aristocracy - it was the Weimar government (social democrats) that had taken away aristocratic privileges - and Hitler also wanted to take credit for that, hence branding them as the true capitalists - (being against the workers) - and the workers were his foremost prey - before the NSDAP became attractive to the bourgeoisie.
You're right. There were 30 different parties in Germany before Hitler. Mussolini also soured on Socialism and left the party around 1919.