Ohio State RB Quinshon Judkins is this generation's Marion Barber III. Judkins and Barber are nearly identical in size and weight (around 6'0" and 218 lbs), and both ran just under 4.5 in the 40-yard dash.
Cam Skattebo is much shorter (5' 9.5") and slower (4.65 40 time). Even though I said Skattebo is similar to Bo Scarbrough, that is a disservice to Scarbrough who was much taller (6'1") and faster (4.52 40 time). As equal in 40 time, Skattebo is equal to Mike Alstott. They both timed their 40 yard dash at 4.65. Only difference is Alstott was much bigger (6'1", 247 lbs).
Cam Skattebo is simply too short (5' 9.5", 219 lbs) and slow (4.65) to be a full-time power back against today's much faster NFL defenses. He likely will be a late Day 3 draft pick and limited in use.