The one that I think should not have been hanged was Julius Streicher. He was killed for his words, not his actions, even though he may have been the most despicable of the lot.
The Allies really wanted to get their hands on Nazi Propaganda Minister Joseph Goebbels. But he committed suicide first.
I suppose the relatively minor propagandist Julius Streicher was the stand-in.
I dunno. If I were a Nuremberg judge, I might have flipped a coin with that guy. As you noted, he was despicable. And he did play a part ginning up hatred of the Jews.
So heads, the noose. Tails, 30 years.