I'm not sure that is true:
Darrin Walls
Harrison Smith
Zeke Motta
are all former ND DBs that are playing in the NFL now.
Kapron Lewis-Moore
Louis Nix III
Justin Tuck
Stephon Tuitt
are all former ND DL who are currently playing in the NFL.
First things first. My original post on this was to address recruiting not development or maturation. The comment was made about us being able to recruit a top 10 RB going forward and I pointed out that we've done a really good job at recruiting RB's so I don't really see that getting much better (margin of improvement). However, we can improve on our DB and DL recruiting by a fair margin. That statement didn't have to do with whether they panned out, developed or progressed throughout their careers. Simply addressing his statement about recruiting highly rated players. FWIW, I don't use this as a good measure normally but it was the measure that he chose for what would be successful.
Secondly, the example above was a very poor effort in proving your point. I pointed out that we've brought in 6 top 15 RB's since 2008 and you put together a list of with very few top 15 players at their respective positions and went much further back in order to so. Again this has nothing to do with development but a statement on recruiting. I'll put together a list below.
This list is of players we've recruited since 2008 that were top 15 at their respective position.
2008
DB: Dan McCarthy, Jamoris Slaughter
DE: Ethan Johnson, KLM
DT: Sean Cwynar
2009
DB: Zeke Motta
2010
DT: Louis Nix
2011
DB: Eilar Hardy
DE: Councell, Tuitt, Lynch, Williams
2012
DB: Elijah Shumate
DT: Sheldon Day. Jarron Jones
2013
DB: Redfield, Cole Luke
DE: Isaac Rochelle
2014
DB: Watkings
DE: Trumbetti
DT: Jay Hayes
2015
DB: Shaun Crawford
So that is 9 DB's, 8 DE's, and 4 DT's over 7 years. Considering that you play 3-4x times (2CB and 2S; 2DE and 2DT to 1RB) the number of DB's and DL to RB's I wouldn't say that they are even remotely close to the same level of recruiting. Now has it been bad? Nope, never said that. What I said was that is was the place for the most improvement, IMO. I think this clearly illustrates that.