I honestly don't think this is a bad strategy - let's face facts, the term 'Student Athlete' has lost all meaning now with NIL, lax drug testing, etc. It has been replaced with "Just don't embarrass the program"
So, with Prime: I think the basic premise is that a grad transfer (22/23 year old adult) will probably be better equipped to play on day 1 than a 18/19 year old kid. This is just natural biology. Along with the physical development, they also have game experience and have proven themselves in the classroom so they will stay eligible. Only a small fraction of players reach the NFL or even solid contributor on the team status so it takes out the guesswork from trying to recruit and develop (recruit is a crapshoot and develop is a crapshoot).
With transfers, he can be selective on who he brings in and a winning program with national exposure will have way more quality people looking to join his team than transfer out. Again, 10 years ago, this was not really possible as stars didn't transfer - now, that is simply not the case.
As for 20% from recruiting - that seems right to me. You go after the most solid locks you can find and you don't need to reach. Also, people need to remember these high school stars 1.) flame out as they face adversity for the first time 2.) fail to develop physically 3.) fail to stay eligible - and LASTLY - if they are superstars, they leave for the NFL early. You combine this with one of these highly rated guys is no longer happy to sit out and develop - if they don't play, they transfer out.
The proof will be in the pudding but I think he has this figured out - he will win - and it WILL NOT BE good for college football as the sport we all love.