McGovern is the same guy he was in his last two seasons here - an average NFL starting lineman. On a loaded team with an MVP quarterback, he's a "glue guy". On a talent-barren offense with a backup QB, he'd be "just another one of Jerry's overpaid vets."
Dude's not a bad lineman and has deserved his nice 4-year guaranteed contract from Buffalo, but he's no Hall of Famer either.
Anyway, I would prefer that we keep the McGoverns and Biadaszes of the world rather than let them walk. Interior OLs take a long time to develop and sign for comparatively cheap in free agency. So when you let them go after 4 years, you pretty much just pay for 2 or 3 years of their job training, and their new team reaps the rewards.