We have to remember not much written material survives from antiquity, and much of what does comes from Arab or Irish copies of earlier documents that date back to medieval times. Almost everything we know from those days is 2nd or 3rd hand knowledge, much of it written by people who may have had their own political or religious axe to grind.

This is why independent manuscripts and archaeological evidence is needed just to try and fill the gaps. Imagine a future historian trying to write a history of the post-Civil War American Frontier if all he had available was a few TV horse operas and Hollywood westerns.