Purely my opinion, but I think Campbell will probably benefit the most from having Rivers as a QB. JB was unwilling/unable to throw quality balls to the seam, and Rivers doesn't have that problem. Same with the deep balls, but I think the seam routes will be far more productive this year.
JB is a safe guy to get us over a short term hump, but I think we all know his limitations. Love the guy, hate his salary, but he's the guy I'd want manning the ship if Rivers was out a game or so. I just don't want to go through another season with the limitations he brings. I'd rather see one of the young kids get an opportunity to make a case for a long term answer.
As for the OP, I think we'll carry 3 QBs on the active roster, and one on the PS. It could be a wacky year with Covid, so I'm more than OK with carrying 3+1. Having the option to protect PS guys is also nice. I'd prefer to segregate 2 of them from the other 2.
I'd actually prefer they segregate the 2 deep (all positions) from everyone else, and also the D from the O. I read something a while back that they're looking at all kinds of ways to keep folks away from each other, including multiple rooms for the same position groups, etc.
If we ever need safety or nickel CB help, he will be considered. One injury to safeties around the league, I am certain he will be considered.
Otherwise, with the addition of Tavon Wilson at safety and Kenny Moore in the slot/nickel role, we really don't need him at this point.
He may want to go to a contender and/or his asking price might be still high. It has to be one of those things for him to remain unsigned.