Again, a lot of the comparables used were 1, 2, 3 years younger than Adley when they made ML debuts. Many highly touted prospects across the game that are now among the "best" at their positions had already posted a solid full season, or All-Star appearances before the age Adley is now (and just starting). Other highly touted catchers like Mauer and Posey had "arrived" and were performing at a high level by age 22 or 23.
I think Adley will be fine. Wieters at minimum, maybe / probably a little better. If MUCH better, big win. But he has to start about as close to "now" as you can get in my opinion. "League average" with the bat for any real length of time and he's WAY behind the curve compared to many other top comparables. The three "ROY" candidates mentioned in the article, basically 2 to 3 years younger.