Remember, Purans contain history of very old and different periods, and history is always Facts plus Presentation, where presentation is 'produced' for specific society accepting that history. History does changes with time and need of societies. Judicious use of interpretation and interpolation is accepted skills of history writers.
Two examples are given below to highlight that "history is always Facts plus Presentation":
a) We have all across the world more than 100 versions of Ramayan. Even popular Ramayan version of Valmiki Ji and Tulsidas Ji, are different at several places.
b) The SAME history, as told in India, Pakistan and Bangladesh is different.
DELIBERATE MISUSE OF SANSKRIT TO FACILITATE EXPLOITATION OF HINDU SOCIETY