@Ice_Ice_Brady
I do agree that bill's way was definitely not the only way and there was other teams that built good teams in other ways. but I still think that bill's way was the best way as far as trying to plan ahead in case there were injuries because every team has injuries. if you build a top heavy team and you lose any of those players to injury you are probably not going to be very competitive. I think the reason that bill's way suffered more is because in 2011 with the new collective bargaining agreement they started reducing practice time and time at the facility. a coach like bill suffers more with that because he's very teaching intensive and technique intensive and he has to have smart, versatile players to make his schemes work. when you lose coaching time you're better off having great athletes and simple schemes.
Just a note to add to what you're saying:
BB and Parcells were able to succeed by building from the defense first. One built from the DL, and one build from the LBs, but both built from there.
You don't really succeed that way in today's NFL.