@Dawson, I agreed with you. There is one path to achieve realisation. Buddha taught the way to achieve Nibbana. Which is eight fold path. In short Sila, Samadhi, Panya. As far as I understand he thought one path. One Nibbana.
But these days there are so many interpretations for Nibbana and the path among different teachers and their students. So is the doubt and confusion.
Either they will get it right or they will get it really wrong. Nothing in between.
Unfortunately these traditions are later additions.