I've been trying to sort out the Justin Evans pick for a bit now and our general personnel evolution over the course of the last few years. My thoughts:
* We've been working on getting bigger up front.
* We've been seeking CBs who backpedal well and have oily hips to turn and run.
* Spence and Smith are LEOish (relentless rusher who primarily plays with hand in the ground, but has the ability to move laterally and get out to the flats with enough athleticism to play in that limited space...lets just not have him moving backwards).
* We spend a 2nd round pick on a Safety who can be an asset in Cover 3 as FS where his hole in run support will be mostly irrelevant as his exclusive responsibility is middle deep third to help vertical routes hash to hash and stay on top of deep-middle-challenging routes (forte is range/acceleration and ball skills while the hole in his game is run support and related).
* Tandy's and Wilcox's skill-sets are very good fits for the other two Safety positions in the 4-2-5 with Tandy handling the Nickel/SS hybrid role and Wilcox handling the Cam Chancelor (SS) role. Conte is sort of poor-man depth for all 3 of those positions. I also wonder about Ryan Smith here (although he's alleged to be slotted for boundary corner).
* We have two fast, athletic linebackers in Lavonte and Kwon that both shown a propensity for being spatial awareness and eye discipline challenged in C2 or T2 zone coverage. Their 4-2-5 C3 zone responsibilities and spatial awareness requirements would be significantly reduced (curl to flat or just flat for Lavonte and their keys would mostly be RBs and TEs rather than having to worry about getting depth for harassing the windows of deep square-ins).
And this seems to be the trending defense for the modern NFL (with the C2/T2 fading out because the rerouting requirements of the coverage and the downhill hits by Safeties are now a liability with the new rules).