Don't let it worry you. Those numbers for interests are inaccurate or rather don't mean much*. The Rivals list of LBs with offers, interest in, or interest from Nebraska numbers 20 or so. (For comparison the WR count is also about 20, QB is a few more than that.)L/B 8 offers but only "3" showing interest, that worries me.
* I was basing my count on what had been entered into the forum, but we are generally only creating topics for guys who have had offers. Guys who we think might get offers or guys that there is lots of interest in like Ron Coleman have also sometimes been entered. Thus the discrepancy.