These provided the basis for Hinduism; also, the epics' heroic battles suggest there was a prolonged struggle for land rights over the fertile plains north and east of modern Delhi, followed by invasions and wars.
The epics' heroic battles have no link with Hinduism. 
mnli hypothesis: The epics' heroic battles have no link with Hinduism.  premise: These provided the basis for Hinduism; also, the epics' heroic battles suggest there was a prolonged struggle for land rights over the fertile plains north and east of modern Delhi, followed by invasions and wars.