arm strength and running abilities could allow him to be that QB that could have run "100% of the playbook". The thought was (probably correctly) that Pyne wouldn't have the ability to do so. Would Buchner have been able to do it given better blocking and running game and a better gameplan/playcalling? I don't know. I don't think anyone knows.
In the end, though, it doesn't matter because Tyler Buchner is out this year. All we have is Drew Pyne right now so we might as well stop making him out to be God's gift to QB'ing in an attempt to win a debate that no longer matters. Let's just pull for Drew Pyne and hope he plays to his abilities as a good quarterback so that we might have a decent year.