At CB we have Vaughn and Watkins and hopefully Crawford will be back (not to mention Troy Pride). That's 3-4 talented guys at CB. Conversely we really only have 1 legit safety in Studstill.
Also in Elko's defense the safeties are more intergangeable (not a FS and SS). Both guys need to be able to cover the deep middle...I don't think Tranquill can do that.