I don't think he's better than a journeyman bottom of the roster WR. He's a replacement level player who is here because he blocks, plays special teams, and brings a different vibe to the WR room.
Honestly, if there is a roster crunch at the end of camp because a guy like Shavers earned a spot I can see Hollins off the roster week 1. Shavers is younger, cheaper, and would fill the same role with upside potential. Hollins has no upside potential.
Davis brought 45 catches, 746 yards and 7 TDs last year. If we got more than 2/3 of that out of Hollins I'd be shocked. 30, 500, 4 to 5 TDs.