There's one thing Justin Herbert and J.J. McCarthy have in common: they've both played for Jim Harbaugh. Outside of that, it's hard to come up with similarities between the LA Chargers' franchise quarterback and the Minnesota Vikings' signal-caller.
Herbert is an elite quarterback among the best in the league. McCarthy has been one of the worst quarterbacks in the league this season, and is entering an all-time territory no quarterback wants to be in. The two pass-throwers represent the opposite ends of the quarterback hierarchy and provide vastly different futures for their respective franchises.