Nah, the so-called 'isms' of India ('Buddhism', 'Jainism', 'Saivism') are called agama traditions. The question scholars face or faced is this: what was earlier? Indologist story that both left wing and right scholars accept is that: there was Vedism, corrupted to become 'popular' hinduism, later Indian Martin Luther (Buddha) fought against the veil immorality of Hindus (because caste system forces immoral obligations on everyone), thereby Buddhism emerging. This is the standard story.