This is pretty big. Not sure if he will play Will here or Sam here but with Robinson/Coleman/Demario they've officially replaced Kenny the Safety/Slot/Sam LB
What I see right now is
WLB - Anzalone/Robertson
MLB - Klein/Te'o
SLB - Davis/Stupar
Since the Sam position is a 2 down spot and Anzalone seems like you may not be able to rely on him for heavy snaps they could also choose to play Anzalone at sam in base(what he played in college) and Davis at WLB.
Regardless they spot filled nearly everything on D. The need Edge/DT right now and that's it.
If they can pull of a DT in FA they could really set themselves up to go QB or Passrusher at 27