There are a few outliers, but by and large, recruiting and final rankings are highly correlated.
http://www.sbnation.com/college-football/2014/10/3/6903749/college-football-recruiting-correlation-chart-wins
This shows that Bronco performed better than he recruited, way above the curve compared to the majority of D1 football.
Having said that BYU has a niche, and that is LDS recruits, and as the size of the elite pool has grown, the % that BYU has been successful with has actually gone down during the last 5-7 years, that is where the focus should be put to regain that lost resource of high end talent.