To what extent were Randall's struggles attributable to injury? To what extent were they attributable to the loss of Shields? It's really unknowable. We can conjecture... for instance, in the games that Shields missed in 2015 (CAR, OAK, ARI, and MIN), Randall came up with two of his three interceptions-- one which he took to the house. I can't claim to know exactly how he played in those games overall, but I don't remember him particularly struggling in those games compared to the rest of his rookie season.
That is the best I can do at trying to build the case, and really it's pretty flimsy. It's just going to have to play out. Personally, I think injuries were the bigger culprit (but not the sole culprit). I also think that players tend to make the biggest jumps of their careers between years 1 and 2, and years 2 and 3-- especially those that had limited experience coming in and are learning a complex defense. With another year in the system and health, I don't see why it's unreasonable to think that there could be a big jump in Randall's performance.
Or maybe he is just going to be a bust and the injuries are merely clouding the reality that he can't play. I'm not discounting that possiblity, I just find it less likely in light of his pedigree and rookie performance.
But I'm not really surprised that TT decided to handle the position the way that he did. GM's with his philosophy don't replace high draft picks this early. And, on the other side of the equation, the options were not stellar. I thought Gilmore would be great but he was really all alone in this market as a proven #1 and he landed 14M from the Patriots , who rarely spend money like that. Even if TT had been willing to offer that kind of money, I'm guessing Gilmore is still a Patriot.
I like how the position was addressed. You've got a veteran who knows the defense and played capably in it in House. You've got a freakishly talented outside corner to add to the mix. You've got Randall and Rollins back healthy. That is not perhaps the big splash move that many wanted to see, but it isn't nothing either. A year ago, you had Gunter playing 861 defensive snaps and Goodson playing 182. Those two might not even make this roster, and if they do will be buried on the depth chart. Barring another bizarre slew of injuries all at the cornerback position, I would expect a big jump from the disaster that the pass defense was in 2016. It;s not as though this is binary and you either have a premier lockdown #1 or you're a mess. Not having Ladarius Gunter, he of the 4.7 forty, as your #1 should prove helpful.