More reps will absolutely cure the issue. If it's a mental block or something just isn't translating 100%, then the only way he'll get better is putting rubber to the road and matching up with opposition.
Burton has played under two OCs, and the general consensus that we heard from interviews is that Scangarello's assignments were too complex, so last year should be considered a wash. Coen is a known commodity, so I trust that he and Stoops know what they're doing. The Scan issues aren't entirely on Burton or Flax, both of whom have improved from last year.
Like others have said, Burton isn't perfect, but when he's good, he's pretty dang good. I'm guessing he gets even better, and it might be like a lightbulb turning on.
For his and Leary's sake, I hope I'm right.