I don't think there's a wrong answer to this one. Along with the obvious – back-to-back SB appearances – that's a great indicator of an all-time great team.
To my own surprise, I went with Sherman. We all know that Earl makes our cover-3 possible, but it's still up to Sherm to effectively take away a half or third of the field for opposing QBs and he's done so consistently for 3+ years. Let's say we have Earl, but Tharold Simon and Cary Williams as our corners. No QB worth his salt is going to avoid an entire side of the field with that lineup. That's the Richard Sherman effect, and no one else on D has it to that level. So if we're considering the drop-off factor to the 2nd stringer, #25 is #1.
I'm also considering film study, game concept awareness, coaching up teammates, and the whole practice and off-field presence. I think Sherman has some equals there in Earl and Wilson, but he's the guy we see consistently practicing the technique he preaches and doing so to make opponents look, frankly, unqualified for NFL play. Everybody knows Sherman's game, yet every now and then a QB just can't resist trying him, and they learn the hard way. The rest of the time they say "no thanks, we'll go somewhere else with the ball... or lose trying." But the vast majority of the time, they don't throw at Sherm because that would be like losing on purpose.
Another qualitative metric: we can count the number of bad games on two or three fingers. OBJ got him pretty good. TY Hilton. Stevie Johnson had a good game for Buffalo a few years ago. Really, that's it though. He never "disappears" and his tackling is right up there with his coverage and ball-hawking skills, CB-wise. His ability to limit YAC when they do complete one on him is huge.
The case for Wilson or Lynch is just as strong, but offense is such a different animal. Wilson requires a spy from most teams, and Marshawn attracts stacked boxes like the warehouse at the end of Raiders of the Lost Ark. But we've seen that if a team can exploit an o-line weakness, or use DB's to re-route our pedestrians, they can shut down either 3 or 24. Wilson has had more than a few stinkers. More than a few teams have sold out to contain Lynch and it's worked. On the flip side, we've seen either Wilson or Lynch step up in those situations and carry the team. So again, each is MVP worthy.
It's a fun conversation when you have so many qualified players. :snack: