Nobody questions that there can be an adjustment period from AAA to the majors. We get it. But what I struggle with is the #1 rated player in all of minor league baseball shouldn't struggle to "adjust" this much.
Texas - Solid start
Oakland - Trash
Chicago - Poor
Detroit - Excellent
Detroit - Excellent
KC - Trash
LAA - Trash
He was never #1 overall, top-10 in most publications.
I think if you look for past top-20 SP, you'll see a lot that struggle early on. Others are really good from the beginning.
I just picked 2017 as a random place to look. Alex Reyes #6, Tyler Glasnow #9, Lucas Giolito #12, Michael Kopech #16.
Reyes good from the start though not for a few years because of injuries. Glasnow bad start. Giolito terrible at the beginning. Kopech missed 3 years for injuries, then relieved, then good last season at 26.
No promises with pitchers.