Sure, Belichick is exceptional at some things coaching-wise, moreso at, say, game management than say, McCarthy. But many folks once doubted that the West Coast Offense would never work without Walsh, too. Holmgren and Shanahan, among others, debunked that theory. The NFL is a copycat league in which trade secrets are not so secrets. Copying Belichick's coaching style should not be too difficult.
And doing things like Belichick the GM is not difficult, either, especially with an ever increasing cap. As I've refrained previously, if Deshawn Wynn is your starting RB, and you have a chance to get Beast Mode, get Beast Mode. It's called an upgrade. If Shields season ended in week 1, you can't just hibernate and hope an undrafted player like Gunter "develops" quickly. If your receiving crop is productive but slothish, and you can acquire a speed fiend like Brandin Cooks for 1st and 3rds, why the hell not?
With an elite QB like Aaron Rodgers on your roster, optimizing the talent on your team with respect to the cap should be the way to do things. Draft and develop is for teams with no shot worth a damn, like the Browns. Draft and develop is just wasting Rodgers' prime, as the saying goes.
Thompson signed a notable free agent once every 2 or 3 blue moons. He rarely ever made any in-season trades. Mostly, he spent the majority of his time as GM drafting and hibernating. In other words, the antithesis of Belichick.
I don't buy the theory that players still don't want to play in Green Bay. Favre and White made playing in cold, dark and dull Green Bay cool again. For those with a longin for the city lights during the season, Milwaukee is only an hour south via car. Chicago, only 3. Plus, plan ticket costs to other urban paradises further away are chump changes to all these highly paid players. It's all about the Benjamins, and the Packers have plenty of them - thanks to revenue sharing.