While it's true that teams with a lot of talent have to face difficult cap decisions, there is a big difference between the Hawks and Niners.
The Niners built a loaded roster by sucking for a decade and loading up on high draft picks. And yes, now that talent drain is starting to hit them, they may well sink because as good of a coach as Harbaugh is, he didn't have to build jack there.
The Seahawks were built from scratch in about 3 years by consistently hitting on lower draft picks.
If in 3 years you can build a team because you hit on Baldwins, KJ Wrights, Shermans, Chancellors, Browners, fleece the Bills for Lynch, and the list goes on and on, then why is it a given that you cannot replace departing players with new talent?
Clearly it isn't easy to do that and stay up for a large window. But is it as difficult as, say, building the team from nothing to SB in a few years?