you shouldn't be using Rothschild and Nazis interchangeably.
There are a number of different theories tying Rothschild and Nazis. One is that Hitler was a Rothschild.
I don't think that Nazis were any sort of group that existed before or after Hitler.
Rothschild to Soros to Antifa
Rothschild to Hitler to Nazis
I just don't see Nazis as something that survived WWII as a functioning, powerful group. They were a group that lost a war. There really weren't Nazis apart from Germany, so you're talking about the German government and other Germans who lost the war. Where is their power base, where do they get their money from? Rothschild - still around, 200+ years after Rothschild got rich and famous.
Rothschild would, though, fund both sides and have them fight, to have people fighting, to be doing something about "the bad thing" as long as the bad thing they were fighting was not Jews or Banking or x,y,z.