IMO, none of those guys on the waiver wire gets you any more guaranteed than who you already have.
If I had to drop one, it'd be Ricky Williams. The only way those free agents wind up being real productive is if someone ahead of them gets injured. But who's more likely to get injured than Ronnie Brown?
Even if Cadillac goes down, Huggins is still running with Tampa Bay's offense -- which isn't explosive. Ricky Williams has a little value even in tandem with Brown. If Brown goes down, Williams is an immediate RB2.
Hardesty is an unknown commodity right now. Leon Washington has to contend with Forsett, a trendy sleeper pick this year, plus Morris. Arizona refuses to give Hightower the reigns, and beanie should get more touches this year than last because his blocking has improved (supposedly).