That's a great distinction between how most of us view ND and how he does, and I think your conclusion is dead-on. I don't think there is a current team that fits this (nor do I think another team will ever be that loaded with future NFL stars), but Miami ~1999 when Davis left would seem to be the perfect setting for someone looking to go down as a legend, as anyone could see that team was locked and loaded for a deep run with even a decent coach. While not quite that level, the teams you mentioned are pretty well set up between loaded local recruiting and favorable schedules (save OU, FSU, Oregon respectively) where a decent coach could easily win pretty quickly, and they're also "name" programs that are either historically or recently elite.
As for your third paragraph, I personally don't think he would be in the beloved pantheon with Rock, Leahy, Ara, and Lou, but he could have easily been just below with Devine as a respected NC-calibre coach with just a little ego shedding regarding his offense and slightly better luck, especially given the low bar his predecessors set. Alabama deserved the 2012 NC, but if KSU didn't crap the bed against a middling Baylor team, we could have easily stolen the title that year and perhaps changed both Kelly & ND's trajectory. We're a cut below the elites this year, but with better luck on the suspensions/injuries and smarter playcalling, 9-3 was well within reach and would have set us up for a legit run in 2015, and 2 NC-level runs mixed in with 2 top 15-25 years gets us just below Alabama/Oregon where we can legitimately claim to be be back. I hate the petroleum turf and inane music, but to his credit he's recruited well and gotten things like the training table, and I genuinely think the job would be far more attractive (although as UT & UF showed, good coaches don't necessarily leave good jobs for ones they perceive as slightly, if any better) to a new coach were he to leave than it was after the last few coaches.
As an aside, someone (edit -ThreeD below) posted this earlier after the banquet evacuation, but exclusive of any coaching decisions, there probably has never been an ND coach who has had this many bad things happen. The Sullivan tragedy obviously dwarves everything else, but there's also been the Teo situation, mass suspensions, inexplicable transfers, injuries at key positions, and so on. It doesn't excuse anything, but man it's been brutal and I can see how he might be frustrated