I hope this won't sound snarky, because it is not meant to be. Anytime you have the opportunity to upgrade a position you do so if financial constraints (and assuming the player is not a locker room cancer) allow. If that pushes the other player to turn it up a notch and win the role back, all the better.
Having the courage to move a Sacha when the decline is near is key. Just look at the Giants. Eli is slower than molasses and nowhere near his former self, but the organization is too scared of the PR black eye to build for the future.
No, it doesn't and I totally agree. You can almost say the same thing about the Yankees regarding Derek Jeter. Only thing is he's got more rings (5) than Eli, and he knew when to step down when it was time to do so.