M Claiborne, T Mathieu, K Sheppard, Lavar Edwards, Lamin Barrow
T. Mathieu was a 4 star recruited heavily by Tennessee, he was not in the rough. Barrow was a 4 star for most of the recruiting cycle but got bumped down to a 3 star during the final rankings. He was from the Nola area and was well know. Also not in the rough. Lavar Edwards was a Katrina displacement I believe who had talent but no real position, and Miles took a chance on him that worked out. Claiborne and Sheppard certainly were underrated by the services, but Sheppard also had a Tennessee offer as Chavis liked his talent since HS.
I think it's a misconception to say these guys were diamonds in the rough. All big programs take chances on 3 stars that they believe have the potential to either contribute or completely outplay what they show in HS and recruiting camps. the ones you listed all happened to work out, while numerous others with similar ratings that signed with big programs fizzled out or never saw the field outside of special teams.