Coming off the Dick Crum era, Mack wasn't walking into a total shitshow. His 1979-82 teams were the first UNC teams to go bowling four years in a row. They beat us in two of those years, once in the Sun and once in the Bluebonnet. Those were the Lawrence Taylor, Kelvin Bryant, Harris Barton, Reuben Davis, and Famous Amos Lawrence years. They'd become a .500 team by the time they canned Crum and brought in Mack, but by and large they were a program on the rise.
Mack went 2-20 his first two years at UNC. No way he sticks around to his big 6-4-1 turnaround in his third year there if he'd laid those two rotten eggs in Austin. He got them to a 6-7 win plateau for a couple of years, then 8-9, and then that 10-win level he regarded as a success no matter what the fuck else happened. Kind of like a gifted student who settles for Bs because they are above average....
Point is, we don't know what Sark's ceiling is because he's not been given the same amount of time Mack was given to right the ship at UNC.