I don’t think you have to have 8 5stars but I do think you have to have 70% bluechip (4star) or better. I’d have to dig it up but I did some analysis on recruiting classes and playoff competitors/champs. It basically came down to the perennial playoff participants had a combined overall former recruit (current player) rating of like 91.5-92 points or higher (bama, uga, Ohio state, Clemson, etc) and the perennial playoff/championship competitors had a player rating of 93 or better. And it takes about 2 classes of this magnitude and a “10+ win per season” coach to get there.
If my memory serves correct (and it could be a bit off), Kirby came in and sold the “dream team” concept. He went from a 8-5 coach with top 10 talent from Richt to an 13-2 coach the next year. His first class was #6. So top talent and certainly he developed them to that 13-2 spot. That said, and it should be noted, Kirby’s first 4 years were identical to Richts in wins and sec/nat champs numbers. The difference later showed from recruiting. By the time his second class (which was #3 with a 92 overall rating) were juniors/seniors (I don’t really factor in covid year with shortened schedule) and sophomores/juniors were the following number 1 overall class (94 overall rating), freshmen were the following #2 class (93 overall rating), they won their first championship.
Note that Clemson did it with top 10 classes.
So really you need top 10 and a couple top 3-5 close together to make it happen these days, plus a coach that is definitely top 25. I believe Heupel is top 25 for sure and if he can get us into that mostly blue chip players a couple top 5 classes with those a few consensus 5stars to make impacts at various levels of the offense and defense, we will win at least one championship, or more.