Jazz is...different. The Real Book is full of mistakes by some Berklee students in the 1970s. Standards as played on the bandstand are very different than what is on the records. The records are all different from each other. The melody is simplified or shortened or embellished, and the chords? Forget it, you'll find out that the piano player likes to play a dominant instead of minor only when you're actually playing the tune. Ask a pro how to think about the harmony of a standard, and they'll explain how they think about the harmony of the variant they prefer.