It seems most people around here have wanted to switch to the 3-4 for years now. Now, there's a glimmer of hope that the Bills might actually do it and most of the comments here are along the lines of "yeeaahh BUT." If you take a gander at Buffalo's roster, the players on defense do not particularly "fit" into any one scheme (especially the zone based scheme they were already running).
Then people start saying things like "well so-and-so doesn't have the prototypical size... blah blah blah." Jay Ratliff is one of the best 3-4 NT's in the game and he's listed at 304 lbs, he might be up to 315 lbs, maximum. It's not as simple as when we were kids putting the square blocks in the square hole. The key to Buffalo being successful is going to be the coordinator of the defense, not the players. The players have the ability, but they're going to need a good teacher because I don't think there's a single player on the Bills that's played in a 3-4 before. No one's ever questioned their work ethic, so if they stay on point why would it be an "arduous" transition... it would be no more arduous than when they all arrived and started learning Perry Fewell's defense... it's not like switching from constitutional law to civil engineering... it's football.
What would Buffalo need (players-wise) to make the transition? Not all that much. Everyone gets caught up in the front 7, but the reality is that most teams don't always run a pure 3-4, they mix in 2 and 4 man lines with it as well. Stroud and Kyle Williams can play NT, but this is really the position where you want someone dominant. I'm pretty sure they can play well there, but whether or not the 2 of them can dominate is another issue. There may be guys available in FA that can be "stop-gaps," (notables are Marcus Spears, Jarvis Green, Johnny Jolly, and Julius Peppers, for the DL in general) and there are probably 2 guys in the draft that could be dominant there that the Bills have a shot at: Terrance Cody and Dan Williams. Dan Williams is more athletic and is a better football player, just not as big as Cody.
The other area of need regardless of what scheme Buffalo runs is LB. It's safer to assume that Mitchell won't be the same player again. So, it's another scenario where the Bills have to add number and skill via FA and the draft (Karlos Dansby, Shawne Maerriman, Antwan Barnes, are notables with several others). If McClain is there at #9, duh... you take him. If he's not, you can wait until the 2nd and maybe shoot for Brandon Spikes, after that you ain't gettin a starting MLB. There are plenty of ways to add the personnel that may be missing... Buffalo just needs to manage their draft and FA well enough to get some guys to OBD that can DO WORK.
Even if the Bills' D stinks next year, I will be much more entertained watching them screw up a 3-4 D than watching them make teams dink and dunk them until corneas burn off.
And BTW, if Kelsay goes back to playing at 280 lbs (as he did a couple of years ago when he was int he DT rotation) he'd probably be a decent 3-4 end. I'd still rather see his $6-7 million spent elsewhere, though. The cynicism and pessimism are seeping in, for good reason, there have been several teams to switch to a 3-4 that were worse off than the Bills are. Look at what the Packers did.... signed some FA's drafted BJ Raji and Clay Matthews, voila, their 3-4 worked pretty darn well until Kurt Warner got a hold of it.