In my opinion, team rankings can be fairly misleading due to their emphasis on the overall size of the class. Because Crean tends to bring in large classes, Indiana skews toward consistently higher rankings.
It is true that Crean has done fairly well if you look at it from a team ranking perspective. Over the last 5 years (12-16) he averages the 6th best recruiting class behind Kentucky, Arizona, Duke, Kansas, and UCLA with an average class ranking of right around 17 (as your data shows) As an example of how class size can skew this, Louisville had the 89th ranked recruiting class in 2016 because they only had one recruit, even though that recruit happened to be a 5 star. So despite the fact that they have had more or less 3 top five classes in that time frame (one was 6th), they aren't close to the top 10 in average.
If you look at things by average player ranking, things look quite a bit different. Indiana finishes 22nd in average player ranking from 2012-2016 behind Kentucky, Duke, Syracuse, NC State, North Carolina, Kansas, Arizona, UCLA, Texas, Villanova, Louisville, Connecticut, San Diego State, Marquette, Stanford, UNLV, Virginia, Florida, Alabama, Maryland, and Michigan State. You can certainly make an argument that this way of looking at things is unfair to Crean as he tends to take flyers on lower rated kids. Adding a lower rated kid to an otherwise talented class isn't really making the class worse but it is dragging down the average. However, I think is a valuable counter measure to looking at this purely by team rankings.
My favorite comparison is Villanova because they come in at 10th in terms of average player rating at 93.92 (Indiana 90.91). The reason their classes are rated so low is that they are always small...in the last 5 years they have taken classes of 2,3,2,2 and 3. Villanova seems to be everyone's favorite example of how you don't need to recruit well to win. I would argue with anyone saying they don't recruit well, they just don't recruit high volumes. In case you are wondering, in the last 5 years Indiana has taken 5, 3, 6, 6, and 5.
