I think you're downplaying this. Time will tell how Mario fares, but if Bama comes knocking, I think any coach will listen, including Mario. He'd be stupid not to at least listen (and create leverage for a new deal). Whenever Saban retires, some fan bases will be tense as **** with the specter of Bama offering the successor $12-15MM a year, plus the keys to that well-oiled machine.
I think Jimbo is the wild card. He's a snake with no loyalty to any program. He'd dip A&M for Bama IMO. He's already one of the premier recruiters in the country and his profile would only increase at Bama.