Great post. You're not going to be a physical team by continually drafting backs whether they're corners or runningbacks. Totally agree you can find runningbacks without using a first rounder, its not that hard. Texans-Foster-free agent, Bills-Jackson-free agent, Broncos-McGahee-free agent, Seattle has a 4th and a 5th invested in Lynch, etc.
Just compare the Eagles and Steelers. I dont think the Eagles with Namdi, Samuel and DRC are in anybodys mind a great defense while the Steelers consistently are. The Steelers have Ike Taylor, Gay and Mcfadden at corner, no 1st rounders and no probowls there. But the heat the front 7 generate is the key. Someday the Bills FO may figure this out. Just think of all the great linebackers the Steelers have had over the years; Greg LLoyd, Levon Kirkland, Harrison, Woodley, Timmons, Joey Porter, Kendrell Bell, Kevin Greene, Chad Brown, Farrior, Jason Gildon and on and on. Most of them, not all, were drafted by the Steelers and a lot them in the first 3 rounds. Meanwhile Bills fans are counting the likes of Merrriman, Moats, Batten and DL turned LBs like Kelsay and Johnson. You give most NFL Qbs all day to throw they're going to find somebody open. It's why fans pull their hair out watching prevent defenses with 3 man rushes. While one sack can be the difference between a 30-40 yard completion and a 10 yard loss. One play and a 40-50 yard difference.
The Bills first three rounds should be all about finding guys who can bring some heat, we can get corner depth in the 4th and 5th rounds.