Wazzu's done it twice with coaches who would have been successful anywhere (including Rutgers, though it's doubtful that Leach would be hired there, as he'd be deemed a bad cultural fit).
The other two are also essentially one coach wonders. Yes, technically Oregon State's was the result of the effort of two coaches, but Dennis Erickson simply maintained what Riley had built until Riley returned to Corvallis from the NFL. K-State's essentially been the result of a once-in-a-lifetime hire, but I believe that they'll be fine moving forward.
That said, I wouldn't lose an ounce of sleep if Rutgers bolted for the AAC. Many equate the program's ceiling with that of Temple, though I'm not one of them. Quite honestly, I'd love to wave a proverbial magic wand, sending major conference alignments back to to 2002. I miss the original Big 12 alignment with Nebraska, Mizzou and Colorado, the Big East with Miami, Virginia Tech, Louisville, Cincy et all. I do, however, love the addition of Utah to the then-Pac 10.
To tie this back to the original topic of B1G expansion, the most pressing issues with the conference, IMHO: 1)As mentioned, divisional imbalance. 2)Several resource-heavy programs -- most notably, Illinois and Minnesota (though, IMHO, Fleck has them back on the right track) -- underachieving almost annually. I didn't mention Nebraska as underachieving as I'm not sure of the program's ceiling in the post Big 12 era. Perhaps a program that equates with the Wisky program (which isn't chopped liver) is the best you can hope for. A return to the Osborne level of success seems unrealistic, to say the least.