I'll happily re-list last year's offseason acquisitions that contributed in a big way in 2015:
QB1 RB1 RB2 RB3 WR2 TE1 RG1 LG1 CB2
That's seven starters that weren't on the roster last year.
I don't know that we need a NT, but needs for defenses starters, assuming no Aaron Williams include:
S1 S2 ILB OLB (pass rushing) DE NT
I think that's worst-case scenario. And it assumes players on the roster like Jairus Wyn, Corbin Bryant, AJ Tarpley, Ty Powell and Tony Steward aren't up for doing what needs to be done to plug some of those holes.
I don't put any of the offensive "needs" out there, because I don't believe they're as dire as what needs to happen on defense.
But I've seen a couple of times now that 2016 needs are being overstated to make the point that Whaley and Co couldn't possibly be up to the task. Everything we've seen thus far indicates otherwise, IMO.