Funny you should mention that...
I actually see room for ONE MORE CB.
Not even a specific name... but more of an ideal:
It would need to be an Iffy Melifonwu type: long, tall, rangy, fast...
Someone who could shift between Free Safety and CB, as needed. So it would have to be someone who has the speed and length to play CB and fight for jump balls (and win them) against taller WR's or TE's, but who also loves to hit like crazy and therefore could swing to FS. That guy would be key depth at both spots. Probably a lot of special teams work, come in occasionally against a taller receiver, or back up Davis and/or Iffy, as needed. If we can't keep Davis past this year: then maybe Iffy or "The New Guy" could be Plan B?
I prefer a CB here over a straight-up safety because (A) versatility and (B) CB's are still in the 4.5-4.6 range at this point in the draft versus the remaining safeties tend to be either smallish and 4.6-4.7+ (or worse) range or bigger and 4.7-4.8+ range (strong safety types).
A safety in this area of the draft is not going to be able to cover as a CB (IMO); versus a CB in this range can CB or Safety (IMO). Which was my point A above.
There are several tall/rangy/hard-hitting CB's still on the board that fit this description. I don't know if Holmes/Campbell "loves" any of these guys, or are thinking along the same lines... but here are a few names to consider (all 6'2" or taller, 4.5-ish or so speed, hard-nosed and love to hit like a truck):
TJ Tampa, Cam Hart, Khyree Jackson, Decamerian Richardson...