I’m basing my views on what I see and read, i.e. the actions compared to the words of all the left-wing ideologues in question. And you are basing your assertions on . . . ?
Based on what I read and what I see, it is not merely “some overlap”.
I agree that Jeremiah 13:23 is a comment on a man’s character; certainly Mussolini’s character was unchanged from his long years as a communist, said communism being all over his repackaging as fascism. No doubt he had read Engels.
There’s been a great deal written about this subject and there can be some common similar policies or characteristics. It’s what makes them different that causes them to be separated into distinct groups..
An easy way to see at least the difference between communism and fascism is to search for a vent diagram on the two terms.