That article is a little bit of an exaggeration imo. Thomas will be missed. In the hands of Bilichick ( a guy who used to coach LT) Thomas will be very effective. Belichick is a defensive genious. Belicheck pretty much created the hybrid lb position in the 3.4. Cannot forget Belichicks defensive schemes that won the Giants 2 sb's also. That is a total of 5 sb's BB defensive schemes had a part in winning. Not trying to take anything away from Rex, but you cannot ignore the players implementing his schemes. I think Rex is a fantastic defensive coach.
The patriots have been more successful at winning, and remaining competitive then the ravens have (IMO). 3 championships in 4 years, wild card win in the playoffs, and the afc championship game this year. I do not think the ravens are "done". I also think they have a fantastic staff, and draft great players. I think they will reload. I thnk this guy is making it out to be a little to easy to find fantastic players. not every day that you find a 270 lb linebacker that can play 5 defensive position, outside/inside in the 3.4., gun punts, etc etc. That might be tough to replace.
I think the Ravens are a great team, with a awesome defensive coach in Ryan. I think that article may be a bit extreme. The ravens will be in the hunt as always this year. The defense is always very good. It is the offense that killed ya.