This swiff knive thing often gets out of control because it makes for a nice story. See Reddick, Haason. Bucannon, Deone. Reddick should've been an edge rusher all along that can do some other things like occasionally drop into coverage. Buc should've been a SS who can come into the box. Instead, both were played out of position and never found consistency aside from a few splash plays. Simmons is a LB period. To be more precise he is a prototype 4-3 SLB that can cover but also blitz if needed. In a 3-4 this role is somewhere between OLB and ILB. He won't ever play in the slot or cover anybody from a traditional safety alignment. He would get roasted by slot WRs or really any type of WR.