I can't ever recall seeing an evaluation that said something like if only he had put up those numbers at 22 instead of 23.
Again, there is absolutely nothing permanent about this assignment. There is zero reason why Walker can't move up relatively quickly. It wouldn't shock me if he finished at AA this season if he hits, as those guys in front of him move to Charlotte and Chicago. Then all of this handwringing over a half of a year is meaningless.