I don't think changing systems was ever going to be an option. I also think Jones would have tolerated some additions that didn't change the basic concepts.As much as I dont like the hire of Debord, this was Butches only option. Like most of you, I really have no idea if Debord will be any good or not but there's no denying that he's not a fan favorite. The expectations of the fanbase are higher than ever because of the recruiting success Butch has had. Butch knows that he cant afford to change offensive systems at this point in his tenure at UT. He has to win and win now. The hot OC's out there were not going to come here and run Butches system, they want to implement their own system.
Butch hasnt won enough here yet to earn an extra year or two because he had to install a new offensive system. If Butch had been here for 7 or 8 years and had multiple 10-11 win seasons, he would've been able to make the sexy hire because he would've been a proven winner at that point and the fanbase would not be questioning if he was the long term answer. I have as many or more doubts about this guy as anybody does, but for right now, he's the right guy for the job. He may not be the long term answer, but with the players we have now, he just needs to be an average OC for us to win 8-10 games. JMO
However I disagree with the idea that this is going to change when Jones has more tenure or success. I will be surprised if he ever hires an OC to make wholesale changes. This is a system he believes in. He believes it has more than ample variability to remain effective. But his focus is always going to be on execution above all else. He's said something to the effect that lots of systems would work if you execute well. Once he gets execution to the level he expects, one of the things that could mess it up is changing systems.
IMHO, future OC's will be promoted more than hired. I think in the scenario you described above where there's established success, Z would have gotten the promotion. I think UT's succession plan from position coach to OC will look like Oregon's does from OC to HC.