Scholar said
Archaeology does not account for the 70 years period and neither does secular chronology.
Of course not! Why on earth should archaeology or scientific dating show evidence for literary myth. How could it? Clue: the cart follows the horse.
There is only one type of chronology at an academic level, there is no such thing as a "Bible chronology" vs a secular one, that is ridiculous. "Bible chronology" is Watchtower jargon used to allow themselves to depart from fact in attempting to prop up their theories.
Then scholar goes on to tell an untruth that Daniel provides the basis for the events of 539 BCE and that therefore his other writings are not myth. This is doubly wrong; a wrong conclusion drawn from a faulty statement. It was not the writer of the book of Daniel who determined 539 it was historians using reliable texts which determined the date. Just like Nebuchadnezzar's siege of Jerusalem in 589 BCE which included the temple destruction by 587 (but depending on which ancient calendar you use to interpret the text -- it could be 586)
'Daniel', not his real name, was a story teller drawing on the events of four centuries before his time, around the middle third of the second century BCE. It was written in an apocalyptic manner to give hope to his compatriots during their prevailing troubles as they were divided Jewish sects suffering from the whims of their Seleucid rulers.
Please learn to distinguish between facts and religious spin.
There is no point in discussing with someone who believes historical fiction as if were truth.