If you're an offense and you know Manning will stay at SS and Quin at FS, then that allows a guy like PEYTON Manning to toy with your safeties.
He's gonna' know the SS will tend to want to cheat down at snap and maybe wanna' sell out for a playaction play. He's going to know the FS will cover a receiver. That ends up making a good QB's job a bit easier.
But if on each snap the FS and SS could interchange duties/priorities, it causes a QB to have to spend extra split seconds to process the play as it progresses. Unless you develop tendencies (a "tell" in poker terms).
In the hands of a competent 3-4 d-coord, it can be used effectively. You can go grab two safeties who have CB'ish skills and trust them to make the right decisions as the game flow changes. Instead of staring at each other and shrugging shoulders and flipping a coin on what to do.
Pollard, IMO, got sniffed out by opposing defenses after his first here year. The next year (last year) he had problems. One-trick pony, to some extent. Being a specialist, like a 4-3 defense tends to ask of you, can funnel things badly if your guys can't excel at it.
Seems a 3-4 asks guys to think in broader terms; to adapt and cross over into areas from time to time. I think it makes guys more instinctual and more hungry to find ways to make plays rather than a 4-3 where the d-line rushes, the LBs plug the middle, the CBs play the wings, and Safeties try to be downfield and used as a "safety" measure in case the d-line fails, the LBs are trying to hit somebody, and the CBs got burned. To that extent, a CB in a 4-3 is not a thinker...he's a lifeguard waiting to be a last line of defense.
Someone tell me if this thinking is flawed; if so, what is and isn't right?