Spence at 21st doesn't seem unrealistic. With a small bit of luck, it's possible. Jalen won't last until 45, however. At this spot, you can take Wright III (who, btw, won't be there in the 4th).
Not sure about the other 4/5th picks.
Clark was awful at the Senior Bowl, Joe Dahl would be better I think. I didn't know Chris Jones, but we have enough DT, I'd prefer an OLB or Cyrus Jones for example. And please, not Oakman, he's just physical attributes and media hype, is lazy and got embarassed at the Senior Bowl.
Anyway, having Tread, Spence and Fuller seem realistic and if it happens, only those three make it a killer draft.