I disagree on "95%", but it's still a fairly high percentage.
The reality on the "5-star OLs" (and even high 4-stars) is that you have to keep them motivated and developing on their current level. We have seen PLENTY of 5-star OL talent get to college and then plateau (everyone's favorite word) or even backslide).
I'm not arguing that Mirabal/Cristobal "developed" Sewell the same way that you do when you take a 3-star talent to the first round of the NFL draft. Now THAT is development. But you still have to do something, you still have to keep a guy like Sewell on a progression level where you are teaching him techniques that go from "I'm just blocking high school ****heads" to "I'm ready for NFL-caliber competition".
Yes, Oregon/Mirabal/Cristobal had a slab of USDA prime beef in Sewell. But the kid could have absolutely been ****ED UP with poor coaching. ****, we've seen that with Miami players in the past, great in high school, meh in college, pretty decent in the NFL.