At robertson redating the new testament moms dating in cleveland
I rather think the logical fallacy with this has been mentioned; but it's really rather theoretical these days.As you know, this methodology produced a date for John's Gospel of 160 . 125 by Roberts &c, demonstrated that this could not be so.
Galatians: A Commentary on Paul's Letter to the Churches in Galatia. Of course, Attic remained the language of purists, or 'academics', and high Koine the language of the educated Koine author, therefore what few major works that have survived are more likely to have been written in one of these variants.