O.K., here's how I see it...
A few years ago, the Cowboys changed from the 4-3 defense to a 3-4 defense thus increasing both the number and quality of the linebackers they would need. They decided to make LBs a draft priority.
They were asking their starting 4-3 DE to switch to a 3-4 OLB, and neither party knew, particulary at draft time, if that would be successful.
After proving that it was a successful transition, their starting OLB suffered a season ending injury. This particular injury is known for a lengthy recovery-time, and for being difficult to return to pre-injury form, thus it jeopardized his return for trainng camp and possibly the season opener. This was known prior to the 2007 draft.
Thus the Cowboys, with LB as a draft priority, now have a group with draft positions, 8, 11, 18, 26, 42 and 103, plus a free agent that was originally drafted at #89.
So whichever 3 aren't starting are the busts. Any one of the top 7 LBs is capable of starting elsewhere in this league and their new team would love to have them. The Cowboys are stacked at linebacker so they can't all start here.
Great problem to have... IMO, none of our LBs is a bust.