No one Underrates anyone, were simply calling it like it is. Harmon has better numbers in almost every category of grading. He also has equal passes defended and more interceptions with a much lower snap count. Yes McCourty offers the teams slightly more versatility because his elite speed, but his decision making is essentially making it even.
This is some words that Pro football focus had to say about the two safeties 3 weeks ago.
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Beside him, it was touch-and-go as to whether Devin McCourty would still be around after his contract expired this offseason. He decided to return to the franchise that drafted him, and he’s repaying their investment. Overall, he’s allowed 20-of-30 targets to be complete for 193 yards, one touchdown, has one interception, and four PDs. Those aren’t elite numbers, but they’re very respectable. With solidity at both outside corner positions, along the versatility of Chung and McCourty’s range from center field, the Patriots have no weaknesses on their back end.
Finally, it’s worth mentioning Duron Harmon, who replaces Chung at safety when he moves down to cover the slot in the nickel. His numbers this year are simply ludicrous. He’s allowed just one completion from four targets for 9 yards, but has three picks and a pass deflection. He’s shown impressive playmaking ability in obvious passing situations, suggesting the Patriots’ secondary could be even stronger moving forward. Harmon now has seven interceptions in his career, despite only allowing 13 completions. Although most of his interceptions have come on misplaced passes rather than jumped routes, that’s still some stat line."
Honestly losing McCourty is a big loss, but of all the loses this team has taken this season, its one of the least important ones. Harmon is a very very good player. This was clear with the way he came in and stepped up in the absence of Dmac last night.
Honestly I think more people have overrated McCourty this season then underrated him. Yes he's a leader, but he's not playing at the high level he was the past two seasons.