I read Barnwell's article, It wasn't a bad analysis, but not as good as you thought. I thought he did a real good job of analyzing JG's performance He also did a good job in noting Brady's dead cap money problem for the next 2 years. But left out one of the KEY factors in whether the Pats should or should not keep JG beyond this season. And that is Jacoby Brissett, who wasn't mentioned once in this article.
JB's presence on the roster makes a HUGE difference in the decision making process, REGARDLESS of how he fairs tonight. I would think that most of us would believe that Brissett is much farther along that JG was in his first year with the Pats, if only because he played major college football in an NFL friendly offense, while JG was playing 4 more years of HS football in a program without a playbook.
JG has come light years from that start over the last 2+ seasons and it a credit to Josh as well as Jimmy for that vast improvement. It's clear he's now a LOT more than the sum of his athletic abilities. Now whether JB can make a similar jump over the next 2 seasons (including this one), has yet to be seen. But nothing he done to THIS point would lead any of us to believe he can't.
BOTTOM LINE - The continuing development of Brissett, is just ANOTHER reason for the Pats to make the most of the asset that JG has become, and I was surprised Barwell forget he was here.