It’s not a books about Zoroastrianism, which is indeed one of the most ancient forms of judaism/christianity.
For Nietzsche, Zaratnurstra, Jesus and Socartes are symbols and counter-examples to be emulated.
Jesus and Zarathustra destroyed the ancient pagan religions as prophetic figures. Nietzsche was a anti-christ like f and anti Zararhustra who did the same thing for christianity and other slave programs.
Socrates is the one who subverted and destroyed philosophy.
Nietsche wanted to be a counter-Socrates, who destroyes the utterly jewed, modern philosoohy and return to the roots of true ancient wisdom, such as Heraclitus.
Just imagine a Business Manual titled thus spome George Soros, which would teach Gentiles how to destroy jews financially and how to destroy the jewish economic system.