Both sides on this are right....
You are making a point in a vacuum while the others are making a recruiting general point, both can be true.
To your point, Simpson cannot say "I" coached, developed and put two players in the first round last year because he didn't and to try to do so would come off as disingenuous. I am unsure what other kids he maybe coached and developed but you are also right someone like Trob and Likens will take former accomplishments with them. Trob isnt saying the system at USCe is what attributed to Horn going first round, **** nah I developed him. Or look at someone like Coach Kul who touted all these underrated guys he developed. Now it is the flipside of that and that is school's always touting alumni.
Bama loses its assistants each and every year, the new guys stepping in 100% sell the "system" and "lineage." Even Simpson with Gwillis put him in a position to be drafted, he had tons of great tape on the field and filled the stat sheets, it was the off field stuff that did him in. It also helps that both phillips and GR15 seem committed to giving back to the school and can help mentor those kids regardless if it is Stroud or Simpson.