Yes recruiting and college football coaching goes hand in hand. But, it does not mean to be a successful coach, you have to be a successful recruiter.
Denson did a helluva job coaching and during his years we got more production out of backs than we have in a long, long time. Several of the players weren't even running backs, to begin with. So, that's multiple points and proof which validates Denson as a very good RB coach regardless of his recruiting. Also, his players backed up his work through their production and statistics on the field. Denson as a position coach outperformed in my opinion. Much like he did as an ND player that was fairly small without much breakaway speed. All he did then was 100+ yard game after game with TD after TD. When you have a guy that can produce, who cares if he's not the best recruiter. Make sure you have that base covered with someone that is.
My point is, as long as you have enough coaches that can recruit well. Which Notre Dame does. Then you also better have some position coaches that raise the level of the kids coming in. ND has been missing this for years, as a whole. Once coaches get the kids it's about a) getting them to perform b) Do they get better.
We saw this with consistency at the RB position, under Denson.