I don't like it, mostly because it would take Matthews, our best player on defense by 2 or 3 heads and shoulders, and makes him less impactful.
After that, I'll break down what I see:
1) Defensive ends: We need two, we have one (Perry) would could put his hand in the dirt and rush the passer. Matthews would be okay as a the RDE on passing downs, but Perry isn't heavy enough to play LDE in base and hold up to the run. So do you play him RDE in base and flip to LDE in nickel? That seems sub-optimal. Regardless, we need to "spend big" on another pass-rush DE to complete the transition.
2) Three technique tackles: We have a lot here. Neal, Worthy, Daniels, and even Raji project here. Wilson doesn't fit in the 4-3 at all, really.
3) Nose tackle: Raji and Pickett, though Pickett's time is running out.
4) SLB: Matthews. No one else on the roster is a complete player--cover the TE, beat the TE in the running game, blitz. Move him to rush-end in nickel.
5) MLB/WLB: Hawk and Bishop, who goes where depends on the specific scheme. Bishop is the better player, so I'd put him whichever is the playmaker, usually the W. But the W needs to be a better, quicker coverage guy. I'm not sure we have that guy on the roster. I'd probably put Bishop MIKE and draft the WILL.
Walden, Zombo, and Moses all get cut, because they don't fit the scheme at all.
We start drafting a ton of defensive linemen, as we'd need to flip our rosters numbers. Currently 6 linemen and 9 linebackers goes to 9 linemen and 6 backers. We realistically have to spend a whole draft just to get the roster numbers looking right.
So there we'd go. We're missing two big pieces--a second complete DE and a coverage linebacker, would spend a lot of roster capital getting the numbers right, and we'd under-use our Game Changer (Matthews) on defense. I don't like the idea one bit. I also don't think it solves any problems, other than giving us a bigger pool of replacement DCs, assuming Capers is fired/retires.