I know it's basktball but Mark Few gets the best talent in the country to come and play Portland and Pepperdine twice a year late at night. I feel like players will gravitate towards winners.
That took Few over a decade of getting a seat at the table (NCAA tournament) and making big noise once he got there. But getting a seat at the table is a lot easier in basketball than it is in football. Campbell's a great coach, but it's not realistic to expect him to have the football equivalent level of success over the next 5-10 years that Few had before Gonzaga became a truly elite program. Especially if he's not coaching in one of the power conferences (which whatever's left of the Big 12 may not be able to claim to be, if this all comes to pass).
I believe he's as good of a coach as just about anyone in college football right now. But he would struggle to do what Few has done if his conference can't consistently get a seat at the table (make the playoff).