Not sure we'll see wholesale changes the first year no matter who is coach. IIRR, most coaches bring in a few beyond the draft and give the rest of the team a year to "try out". I suppose that if they know they don't fit their style then a player will be gone or if they figure out a way to make a deal that gets them draft picks or a player they covet they will make those moves.
Bottom line is that it does take years to turn over a roster and in the mean time, we may find that our roster wasn't the lion's share of the problem.
Take our O-line for example. Doesn't it appear that it has taken a step backward this year after looking like it was getting pretty decent last season? Is that coaching? Is that lack of belief in a system? Is that full implementation of the Boras system and therefore we have a pretty full picture now? Would a change in coach and system get more out of these guys? These are not bottom of the barrel picks for O-linemen. It wasn't just the Rams that thought highly of them. And they are still young enough that we may have not seen their true potential.
Either way - I am not sure that we will see a huge change in personnel. And personally, I'd rather find out that it was coaching. Because honestly, that is what is going to see the most drastic change. And I'd be stoked to see Quick as a 1,500 yard receiver for Goff, Gurley getting the holes he seemed to get last year, Tavon breaking ankles across the field, Higbeast rumbling down the seam, Cooper moving chains, AND keep churning the roster with draft picks - not FAs.