Just 13 games and we are already at this question? No. He is not overrated, certainly not as a coach. I think as a GM is a separate discussion.
Bill, just like any other HC, he is dependent on having good players. He has said this time and again. It is a players game. He does not have good players right now. He is most deficient at QB which is why the team is 6-7. When he finds another legit QB and adds some more pieces at the skill positions we will be contending again.
This has been true of Bill's entire coaching career. Here are some stats that I had posted on another thread.
Bill's record:
With Tom Brady as his starting QB: 224-66
With anybody else as his starting QB: 55-71 = 126 games = approx. 8 seasons worth of data as HC
With anybody else as starting QB with Pats: 25-26 = 51 games =approx. 3 seasons worth of data as HC
You can make the case that outside of Bledsoe, Bill has had average (Cassell, Jimmy) to below average (any of his QBs in Cleveland, Newton, Brissett) Qbs to work with and as a result he is a below .500 coach. When Brady came, he became the GOAT because he had the GOAT QB. That is how it works in the NFL and in every sport when you have a transcendent player at the most critical position. It was true with Montana as well.