In terms of recruiting, Tennessee is a bit landlocked, so to speak, given developments beyond their control.
The State of Tennessee has never turned out a great deal of talent, and in recent decades Tennessee has always been heavily reliant on going into border states, which was not a major issue, given that the State of Tennessee borders nine other states. UT typically did well enough in-state, and then went into Alabama, Georgia, the Carolinas, and up into the Ohio River valley to get talent, and that strategy generally worked really well. Fulmer used it to perfection in his heyday.
The problem for Tennessee in recent years, however, has been the rise of programs in those surrounding border states. Alabama is at all-time high, Auburn has done really well the past 10-12 years, ditto for Georgia, Clemson recruiting has been strong, and South Carolina is also at an all-time high. Incidentally, the return-to-power of Ohio State this decade has locked up much of the Ohio River Valley, and several other programs have made significant in-roads into the mid-Atlantic region. Combined it all worked to really limit their recruiting base.
Look at it this way, kids like Tee Martin, Fred Weary, and Joey Kent (Alabama), Jamal Lewis (Georgia), Albert Haynesworth (South Carolina), and Peerless Price (Ohio), aren't saying no to the Mike Duboses, Terry Bowdens, Ray Goffs, and Brad Scotts of the college football world and signing with Tennessee anymore. They are saying no to the Vols and signing with Saban, Spurrier, Richt, Meyer, etc.
Again, events beyond their control have really limited their recruiting base, and it has hurt them significantly.