Injuries always slide guys a bit. Here's some more with some concerns that have to be vetted and could explain if they do fall or are already project to (not all were serious):
CB Derek Stingley Jr, WR Jameson Williams, CB Andrew Booth Jr, DT DeMarvin Leal (and off-field), WR John Metchie III, QB Carson Strong, CB Jalyn Armour-Davis, RB Zamir White, RB Abram Smith, WR Jalen Nailor, TE Jelani Woods, TE James Mitchell, TE Chig Okonkwo, OT Rasheed Walker, OT Kellen Diesch, OT Matt Waletzko, OG Justin Shaffer, OT Zach Thomas, DE Travon Walker, DE Logan Hall, DE Drake Jackson, DE Josh Paschal, DE Cameron Thomas, DE Alex Wright, DE Christopher Allen, DE Tyreke Smith, DE Jeffrey Gunter, DT Neil Farrell Jr., DT Kalia Davis, DT Noah Elliss, DT Marquan McCall, DT D.J. Davison, LB Troy Anderson, LB JoJo Domann, LB Terrel Bernard, LB Mike Rose, LB Jeremiah Gemmel, LB Aaron Hansford, LB Baylon Spector, LB Jeremiah Moon, LB Jake Hansen, CB Cam Taylor-Britt, CB Marcus Jones, CB Akayleb Evans, CB Josh Jobe, CB Mario Goodrich, CB Isaac Taylor-Stewart, S Percy Butler, S Delarrin Turner-Yell, S Quentin Lake
As far as additions to off-the-field/maturity I'm aware of: OT Dare Rosenthal, OG Ed Ingram, DE Jesse Luketa, DE Isaiah Thomas, DE Michael Clemons, DE Tre Wiliams, DE Adam Anderson, DT Devonte Wyatt, S Bubba Bolden
Age probably won't factor in much given that there are so many 23 or older. Maybe the guys that are pushing or over 25, which includes OT B. Raimann, LB J. Domann and WR V. Jones are going to be relatively cheap I think.
Here's a pretty good list of those 23+ (rounded of course)