Harrison is already playing as the best NT in the NFL and Ellis is probably better than most teams starting NT, so that is really one position I could care less about when it comes to other players.
It's always important to get more and more good players, but the above is true. Snacks has turned into a monster. Rex and Dunbar deserve a ton of credit for that. Ellis is also very good and would be starting in a typical world if Snacks didn't turn into the player he is.