I'm not sure what our cap situation is this year, and what we're trying to roll over for next year, but Sherm is on an extremely value contract.
If we were able to get an extension done, I would theorize that it would make sense to sign him now while the cap is lower, then pull forward some of that money in the form of a signing bonus. This spreads out the rest of his contract and makes the cap hits later easier to take. Plus the cap is expanding, so we'll have enough to sign a guy like Wilson. Plus, we need to sign Wagner coming up as well.
I honestly don't like paying Sherman 13 mil/year. He's worth it, but I'm not sure he's worth it in this defense. It's too simplistic to say that Thomas makes Sherm's job easier, but they work together. Sherm also makes Thomas's job easier.
Looking at Maxwell and Browner before him (although Browner was a bit of a physical freak), it doesn't look like it's going to be hard for Carroll to find talent and plug it in at a high level in his defense. I'd theorize a good Nickle Corner is harder to find than a lengthy guy that can play on the outside in Carroll's defense.
Then again, I could be totally wrong and we've just gotten really lucky with talent. Maxwell would've been cut by almost any other team out there. We were patient and it paid off.