If they bring back Nixon and you can bank on better health (and performance) from Jaire and Stokes, then I agree CB isn't a big need. I'm not sure how good Nixon is as a man corner in the slot...his agility is poor by NFL CB standards. Valentine is a steal for a R7 guy. I think they need to get better at slot corner, and hope for good health. Hope's not a great strategy, and corners get hurt a lot since they are always running around on the field... and the adage about never having too many good ones is true. I wouldn't spend a high round pick on one unless that's where the BPA is, but I could certainly see them take one in the middle rounds.

The safeties were seen league wide by scouts and evaluators as...not good. You absolutely have to improve on that. Even if I like any of the players from last year, there is plenty of room to improve and upgrade. NFL roster building is different in that you can't just stand pat or be content with your guys - you're either getting younger and better, or older and worse. Ford was hurt, but he was also inconsistent and was briefly benched early in the season. Inconsistent actually describes most of the safeties. Owens is ok depth and had a few good games, but he's not good in coverage and got embarrassed tackling more than he should. Johnson Jr., screwed up on the Kittle TD, by that point of the season he should know where to be on the field. Maybe that's coaching, but he's also in his 2nd year of playing safety, I don't know what you can expect from him.

It's not about "grass is greener" elsewhere, it's that the grass in the back end of the defense had a lot of brown spots, and you have to add water and nutrients (by way of draft/FA) to revitalize it.

If a player enters FA and they were 'just ok' or 'not good', why bring them back unless you HAVE to? You've likely already had enough time with them to gauge the extent of their upside and limitations. If there's someone better or more promising out there you have to take a look. Loyalty is a great quality, but not with roster-building -- GMs have to be ruthless or they end up with old injured Randall Cobbs eating up their cap space and costing them their job.