Biblical Studies by Methodology
A focus of our methodological approach as applied to biblical studies is having objective/external witness verify a claim or assertion made
The Bible itself describes this as having 2 or 3 witnesses to establish a claim. It furnishes proof
In regards to authorship in biblical studies this is done by comparing two competing (and often controversial ) both views side by side and seeing which one actually has external proofs to back it as true.
In order to refute some assertion which has external backing it isn't sufficient to merely make claims but external/objective evidence to the contrary is needed