Pete's philosophy is fine and proven to work. The principles - dominant, physical running game, explosive and efficient passing game, and a great defense - work in any era and in any weather conditions (i.e. January). That said, he and JS have somehow strayed from that in a variety of ways since 2013.
1. Harvin trade, which in essence allowed Tate, a far better and reliable player, to leave in FA.
2. Graham/Unger trade, more so because Graham's fit in the offense is questionable.
3. Letting Okung go without any plan in place for a viable replacement. The fact is that the offense has been much more erratic since Okung left.
4. Drafting guys early as tackles when it doesn't appear they can play tackle (Odihambo/Ifedi).
5. Cutting Jhari Evans to be cheap and young only to see Evans playing well elsewhere.
6. Signing Lacy and Joeckel to deals that seem to be way above their market in lieu of a viable starting OT.
Meanwhile, they are headed to the point where the defense ages at once and goes from being elite to overpaid.