Honestly, two years ago they backed into the playoffs in a most unbelievable way. IOW, they got as lucky as hell when the Bungles converted a 4th and 12 for a late TD against a decent Ravens defense. The Bills did NOT control their destiny there.
As for the rest of your post, you make some good points but I STILL see a LOT of UNdisciplined acts by the Bills out on the field, so the latter tells me that coaching isn't as good as you think it is.