The one constant of the NY Giants, Cleveland Browns, NY Jets and NE Patriots was that when Belichick was there, they did better. With lots of coaches very highly regarded moving on from the Patriots, and with Brady being injured one year, the team with Belichick keeps winning. I'm thinking the X-factor is … Belichick. Now, I hope you're right. I hope Flores is the exception to the Belichick coaching tree … but I'm not betting on it, just crossing my fingers.
IMHO, Belichick doesn't teach his coaches to duplicate what he does. Here's hoping that Flores is very good at figuring it out from observation, which is a hard way to learn coaching.
I'm not going to argue that Belichick is not a good coach. However, without Brady at QB, Belichick has been a below average HC. Bill Parcells, Pete Carroll, Marty Schotenheimer along with others have fared better with QBs other than Brady that Belichick has coached. And of course Brady has not played under any other HC other than Belichick.
The 2008 season had mostly to do with the AFC East getting to play a cupcake schedule being matched up against the AFC West and NFC West.
Out of those two divisions only the Cardinals had a winning record at 9-7 and that is because they went 6-0 within their division which was horrible. Those two divisions were so bad the NFC West went 13-33 in games outside of their division and the AFC West went 14-32; combined those two divisions went 27-65 outside of their division.
The soft schedule is how Miami went from 1-15 the year before to 11-5 that year. Miami went 7-1 against those two conferences 4-4 against everyone else. The Bills went 6-2 against those two conferences and 1-7 against everyone else.
New England went 7-1 against those two divisions, swept the Bills and split with the Dolphins and Jets to get to 11 wins. Two years later in KC, Matt Cassel put up the same starting record (10-5), made the playoffs and had a much better year passing than under Belichick.
Drew Bledsoe was 5-13 under Belichick at NE and was in his prime. Bledsoe was 32-27 under Parcells and and 26-20 under Pete Carroll in NE previous to Belichick. Bledsoe went to Buffalo and was 23-25 (14-18 under Gregg Williams; 9-7 under Mike Mularkey) as a starter and 12-10 in Dallas (under Parcells) after leaving NE.
Bernie Kosar was 30-17 under Marty Schottenheimer in Cleveland, 12-16-1 under Bud Carson and Shofner, and 11-18 under Belichick.
Vinnie Testaverde went 16-15 over while in Cleveland. Testaverde tenure with Jets that began 3 years after leaving Cleveland was 25-16 (12-2 under Parcells).
As for overall record with and without Brady...
Belichick with Brady at QB
207-60 (18 winning seasons; 0 losing seasons)
30-10 in playoffs (6-3 in Super Bowls)
Belichick without Brady at QB
54-63 (2 winning seasons; 5 losing seasons)
1-1 in playoffs (Wild Card win)
The problem may not be other coaches in Belichick's tree can't duplicate his system. The problem is they can't duplicate his QB, Tom Brady, that has brought him most of his success.