The old saying goes, "A bird in the hand is worth two in the bush."
I believe sometimes, the best thing schools can do, as far as recruiting and personnel changes go, is re-recruit players they already have on their teams.
Yes, you want to bring in the best talent available and players that fit your program or players who will thrive in a system you can run.
A lot of time is spent getting these players into your teams' training, strength, conditioning and practice regimen. Players take time to adjust to the higher level of competition and the speed of the game at the higher level.
So once those players become redshirt sophomores, juniors, and redshirt juniors, seniors and redshirt seniors, they are the personnel getting most of the starts and being trusted in leadership positions and in certain game situations. They have experience and prior coaching to pull from.
Not every team can go out there and recruit top-5 ranked classes and it is hard to forecast some of the positions that will need to suddenly have an influx of players (due to injuries, suspensions, transfers, poor play, etc). When this type of stuff happens, it usually takes place after the season has started but well into the late part of the next years' recruiting cycle - a time of the year that is hard to suddenly go out a grab a few gret players to fill that vulnerable position and build depth.
So sometimes the best recruiting coaches and coordinators can do is to re-recruit players and get them to stay in school for another year.
Of course this can be seen as selfish and it totally is. That is part of the point too. To go into this mode of thinking requires the thinker to put the needs of the school above the risks the individual player is asked to take on.
Yech, I can hear you misspelling words as you speak!