Let's see. Schultz is a very good but not dynamic pass catcher. Sucks at blocking. Your 2 rookies are close to as good at pass catching and much better at blocking - especially Ferguson's blocking. I'd let him walk unless he took lots less than he was asking last year.
I'd sign both Brown and Lewis if they would take reasonable contracts. That means Diggs and Bland starting, and you can play with the backups like they already are now. I am not crazy about Joseph's or Wright's play, but I suspect Quinn hasn't given up on Wright yet.
LB has Parsons and Clark for sure, but all the rest are questionable to me. I wonder if Andre Carter could be that unicorn MLB Dallas needs.
DE has Tank, SWilliams, Fowler, and Armstrong with Watkins able to slide out if needed. no Upgrade needed.
S has DWilson - resign, Kearse and Hooker, with descent backups......I like the group. Upgrade only if one falls in lap.
DL -- nothing there that couldn't be upgraded, IMO.
QB starter is financially set regardless of perception of his play, no reason to think Dallas would look for anything but a developing backup.
RB -- here is your question. I don't think if I were Pollard, I would stay -- I'd want my own gig where I was the known starter. So you have an overpaid Zeke - loved by ownership. If Bijon Robinson drops, I just might take him and cut Zeke post June 1. Go into next year with a new hungary RB. If he isn't available, I'd draft one later and partner him with Zeke for a year or so.
OL -- I'd sign both Biadasz and McGovern as long as they didn't want too outrageous of contracts, as well as signing Steele, and then I'd add a couple of developmental guys in the draft. Tyron is going to retire some day, but you already got his replacement in Tyler. Steele is still young enough. Ball and Waletzko are questions, but you know by next year if they are keepers.
WR -- I like CD. Gallup gets no separation now. TY Hilton getting over the hill. Brown is a JAG, and not sure the rest even warrant calling them JAGs. So one WR needed, IMO, although it doesn't have to be a 1st rounder for a #1.
So needs as of now. DT, then WR, then that elusive MLB, then another two IOL and a CB, and developmental QB.