DT, DE, S would all be huge reaches at #10.
LB is probably a reach because there are no sure things at LB, just hyped guys who run fast who may play several positions, but none who shed blockers and stuff the run between the tackles.
CB, to me is the only position that you can draft at 10. Surtain is fine at 10 even if 1-2 OTs or WRs are rated a little higher. Horn is a reach at 10, so you have to trade down. You cannot draft him at 10 unless you had him rated higher than Surtain for fit in your defense and are willing to stand by that when the media is blowing you up.
For me, it has to be Pitts, Sewell, Surtain, or Slater......Chase would be a value pick as he will replace Gallup for the next 4 years and make your starting group even better; plus, if he plays like a stud, you can then let Cooper go in a couple years and make him your #1. But I don't see how you take Chase if any of the other 4 are still on the board.
My ideal would be Pitts, Sewell, Surtain if the experts and coaches are convinced he's a stud, or a glorious trade down.