You are mixing up a lot of timelines (mostly in AD) and hence not a good comparison.
I am talking about records from 5000-7000BC (deducing from Sanskrit literature) by which time they had already been orally transmitted for eons. So they are truly ancient with layers upon layers of grafting of realities/myths/stories over time.
There is nothing in Sanskrit literature that securely old. The Vedas already postdate the mixing of Indo-European speakers and the people of the Bactria-Margiana Archaeological Complex, and we know that was much more recent than the fantastical ancient dates that are passed around laypeople in India.