It's not a matter, for any of our coaches, of not having been aware of certain kids having issues which made them relatively high risk. It's a matter of believing that those kids had the potential to be significantly better than other kids whom we could get who didn't have red flags. Even Nehlen recruited kids who either failed to qualify or washed out because of academics or behavior without ever contributing. I do think Rodriguez and Stewart took chances with too large a proportion of the classes, whereas Nehlen took fewer and preferred to take more "lesser" physical specimens and put a lot of emphasis into developing players.
I do think we should take some chances. We're not an elite program and won't get many of the "sure things" on and off the field (quotes because no one is a sure thing, even Bama 5 stars don't all excel), but I agree we should be more judicious.
If we consistently have classes where 2 recruits become "stars," 6 become solid starters and another 4 become capable multi-year contributors, we will usually have good football teams.
A team doing that would usually have 16 or so junior and senior starters with a few excellent players in the mix, a few sophomore and freshman starters (who would be the ones most likely to become "stars") and enough quality depth.
If you have 36 legitimate power 5 players in your upper 3 classes and 3-4 RS and true frosh ready to contribute, depth is not your problem, except maybe occasionally at an isolated position or 2. You might, though have a problem due to a lack of elite players among them which can be the difference between being mediocre and very good. That's why our coaches all have taken chances.
"Depth" is one of the most misleading concepts used by coaches in explaining current problems. Teams don't lose games because they don't have 3rd stringers at most position ready to compete at a high level or even because they don't have 22 2nd stringers ready to compete. A lack of TALENT among the core of 35-40 who are going to play 95% of the meaningful snaps is obviously a far bigger factor. Using the talent to fullest advantage by developing talent, teaching technique and skills and coaching in devising gameplans and calling plays are all also much more important factors than the quality of the players standing on the sidelines during games.