Take a look at the presumed starters on both sides of the ball:
OFFENSE:
QB – Matt Flynn
RB – Marshawn Lynch
FB – Michael Robinson
WR – Sidney Rice
WR – Mike Williams/Kris Durham/Ricardo Lockette
WR – Doug Baldwin
TE – Zach Miller
RT – Breno Giacomini/James Carpenter
RG – John Moffit
C – Max Unger
LG – Duece Lutui/Paul McQuistan
LT – Russell Okung
DEFENSE:
5-Tech DE – Red Bryant
DT – Brandon Mebane
DT – Alan Branch
LEO DE – Chris Clemons
SAM – K.J. Wright
MIKE – Bobby Wagner
WILL – Leroy Hill
CB – Richard Sherman
CB – Brandon Browner
CB – Roy Lewis
SS – Kam Chancellor
FS – Earl Thomas
Players like Lynch, Rice, Baldwin, Okung are system-agnostic. In fact, the only players who would seem to be at risk of losing significant value under another system would be Paul McQuistan, James Carpenter, and John Moffitt. The offensive line is run differently, but that’s more a Tom Cable dependency than tied to Carroll.
The defense is Carroll’s baby, and not surprisingly, contains more risk. Bryant, Branch, Clemons, Sherman, Browner, and Chancellor all would be at risk of seeing their value diminish. We have already seen how Bryant’s value was as a defensive tackle. Branch was a middling player in Arizona before arriving here. Browner was in the CFL. Even the great Chancellor is a rare breed. Most NFL defenses are using two smaller safeties. The days of big thumping safeties has largely come to an end. Sherman is a good enough athlete that he could possibly work in other defenses, but Browner is harder to picture succeeding elsewhere. That’s not even bringing up newly drafted Bruce Irvin, who is slated to take over for Clemons as early as next season. Clemons was a role player on Oakland, a reserve in Philly, and a revelation in Carroll’s LEO position. Irvin should have value as a pass rusher in any defense, but would play far fewer downs. That’s why Irvin makes perfect sense to Seattle as the 15th pick, but may not have been picked in the first round by a number of other teams.
Carroll leaving may seem like a far-fetched idea given how much great progress the team has made thus far on the roster. Consider the possibility of the Vikings, or another team, moving to Los Angeles. Carroll’s roots are in California, and the ownership group could pull out all the stops to entice him back down there. The upshot is that Gus Bradley runs that defense, and has head coaching potential. He could take over for Carroll without losing the defensive philosophy. That makes it imperative that the team keeps Bradley around, which will be harder and harder as the defense gets more recognition around the league. Carroll and Schneider have the team headed in the right direction. Their direction. That unique configuration of talent is a big part of what makes this team exciting. It also adds risk to the longevity to this upcoming run toward a championship.