What would convince you of causation?
I think we can agree that Enneagram and Jungian typology focus on different aspects in your psychology. Jungian is more about how the brain operates and Enneagram is more about your drives, motivations, psychological hindrances etc. Both of which are strongly connected with each other. For instance, introverts won't develop a 7-like pattern and psychological hindrances or occupations, because they both cancel each other out. It is like saying people can be "ambiverted". But sure, there are people who make cases for ambiversion. But then you fall out of the Jungian frame.