Agree Bills should probably still be considered the best team in the league at the moment despite the loss; they're simply too talented not to be. Miami is in very good position at the moment right behind them, though, and despite their loss to the Colts, Kansas City should probably still be considered an upper echelon AFC team as well. For now, Philadelphia can probably be considered the best NFC team; Los Angeles (Rams), Green Bay, and probably Minnesota despite the Week 2 loss to the Eagles would be behind them as I see it.
I had doubts about the Giants myself, given neither of their wins thus far had been against that impressive of opponents, and I suspect they may now regress to the expected mean. Not sold on the Cowboys as of yet either; neither of their wins were over a very impressive team as of the present, and they're going to need to score a lot more points to keep up with the better teams as the season progresses.
Would it be possible to simply flip the Chiefs-Buccaneers game to Kansas City if needed, or is someone else using Arrowhead Stadium on that date?