Yes, Ramayana and Mahabharata are old indigenous folk tales with no connection to Vedas. The connections were inserted later.
Now it proves you haven't read Mahabharata and Vedas.
There is a king Rama and his clan Ikshvaku(this clan is named after 'sugercane' so give rest to your Arctic fantasies) in Rigveda. Great ancestor Manu was the progenitor of this clan. Same way Yadus are present in Vedas but they were enemy of the Bharatas and in Mahbharata the Kurus(who claim to be the decendents of Bharatas) had been decimated and replaced by Yadavas so yes Mahabharata's core narrative is political. These Kurus are supposed to have their origin in Uttara Kuru which was probably in the north of Kashmir/center Asia so they were not exactly 'indegenous' as you claim them to be. Same way I doubt that real Rama was in Ayodhya. Instead those Ikshavakus could have set their kingdom at the bank of Harayu river in Afganistan. Yadus have been described as southerners(as compared to other Vedic clans) and we have archeological site of Dwarka which proves that this city was not just a myth. A son of Devaki named Krishna has been mentioned in Chandogya Upnishada and it's alright Mahabharata is a post-Vedic narrative. So here goes your 'indigenous' theory to the gutter.
Both Mahabharata and Ramayana are full of Vedic themes. Moreoevr Mahabharata's side stories about the Vedic characters are not actually insertion but the degradation of these historic figures. Yes Mahabahrata has been lowkey maligning many ancient rishsi. Their stories are different in Vedas.