No because you edited your post and added the study. The difference between 1 (92% for center) and 12 (27% for WR) is statistically significant. All the PFF data showed me is that teams will take more swings on premium positions in the 1st round leading to a higher bust rate than the rare non premium positions where only the best of the best are drafted in the first round. Plus, even after saying that over 50% of CB's in the PFF article panned out as Day 1 hits.
You kind of lost me when you said that you could find quality starters in the later rounds and used Dane Jackson as an example of this as he was almost dead last in PFF grading last year to the point they just benched him after week 11. What's the hit rate on CB's from round 2 to 7 since they are so easy to find?