Ouchie-Z-Clown
I'm better than Mulli!
I didn’t want to go here, but it’s where I’ve arrived. I think you may be right.I think Simmons is best used as a TE matchup weapon in coverage. I look at his comps (imo) Kam Chancelor and Thomas Davis and think that using him as a base S (or base over LB) and then a nickel LB is easily the best use for his ability. He can 100% lock up TEs. He has shown that and vs premium TEs this is how you use him.
Against the run, you have to have him away from the ball so he can run and chase vs read and react OR have him on an EDGE where he sets the edge or pursues backside. That is why I think he is a base S or base over OLB. Personally I prefer the S position in base because he is away from the ball in the run game so he can see and attack but also gives you a size matchup vs TEs in the passing game.
As a nickel I agree that you don't want him matching up vs many slot WRs. I like a zone nickel LB who can spy vs mobile QBs, man vs backs out of the backfield or blitz. I think those things make the best use of his athleticism and maximizes his versatility.
Also, keep things simple and keep him playing fast.