Just to do some more interesting things... I think you can somewhat see why Henderson struggled when you look at his classes:
Let's start with 2010:
Littrell 160
Gott 294
Reida 379
No other player that came to UK (or at least I don't remember their names) was inside the top 500 players. To be fair, we did have some good ones in the "Top 1000" group: Riddle and Witt.
2011:
Cousino 215
Shepherd 261
Fettes 316
Reed 406
Kuhn 439
Drake 500
This was obviously a pretty solid class with a good group of top 500 players. No coincidence what they helped us accomplish.
2012:
Cody 321
Casey Schroeder** 343
Combs 390
Arnold 500
Storm 500
This class is weak. Starts with no one inside the top 300. Not a lot of high impact players other than Cody there.
**Played just 8 games at UK before transferring. Went to Coastal Carolina. Went to the CWS and was an 8th round draft pick and is now in Double A.
2013:
Hollon 28
Green 29
Heady 88
Clifton 134
Zeigler 330
Shelby 411
Brown 430
I put in bold who went to UK and who didn't. Zeigler was here for a few years, but I don't think he was that impactful. UK went all in on getting some top targets inside the top 100 and missed on 3 of 4, 3 of which were pitchers. Class turns out somewhat solid, but after this core group there is no one even in the top 1000, everyone else is listed as a 'high follow.' However, we do get some good ones from that group (Salow and Squires).
Pop 116
Lewis 365
Mahan 500
Schaenzer 500
White 500
Again, we get 5 or so guys in the top 500 and the rest of the class is 'Top 1000' or higher. Some good names there, obviously.
Anyway, my point here is that it seems to be that the trend is to get 4-5 top 500 guys and then there seems to be a big drop. Some years we aren't getting anyone inside of the top 300. That happens in 2015 with no Henderson recruit coming to UK lower than Josh Smith at 306. That class looks much better due to JUCO guys thanks to Mingione. Still, these, IMO, don't look like consistent good classes top to bottom.