I dont wont discount cultural elitism taking play to some degree in the general perception between the two

But that being said written records do allow the records to survive and be examined a bit easier. For exame you could start checking the historicity of something by seeing if someone else wrote about it. If say the Babylonian, Egyptian and Asyrian records all agree that an event went a certain way (especially when those areas were independent from each other. Seperate kingdoms dont have as much of a vested interest in telling the same story) all record an event the same way from roughly the same time period there's more credence to the telling. 3 seperate oral records are less likely (in general) to have come down through the ages than cuneiform tablets.

You could also potentially trace translations and versions of the story through time to see how it morphed and evolved in the retellings or when being translated. That would be something like comparing the dead sea scolls to a modern old testament/Torah. How much it varies overtime and what varies over time can give hints and clues.