Yeah I don't see many paths where Sirianni or Culley are one and done.
Sirianni especially is getting handed a dumpster fire in Philly, and there's no way anybody in leadership in that organization can expect that to be a genuine competitor for the next few years. They're going to cut or trade a bunch of players off that roster, and they're aging in a lot of spots. Plus, one and done firings are pretty rare in this league.
Fangio, Nagy and Zimmer have biggest hot seats in the league, no question. Any missed playoff appearance by any of those three will likely result in getting fired. Among the other guys I'd suggest...
Mike McCarthy in Dallas
Kliff Kingsbury in Arizona
I think Zac Taylor has a longer leash than people think. They held on to Marvin Lewis for a long, long time, despite not being very good at his job, so I think he gets longer than people think. We can talk about "surprise" firings, but we also didn't have any of those this offseason, and in fact, the "surprises" were how many coaches kept their jobs that we thought were going to get fired, namely Fangio and Nagy.
Kliff Kingsbury probably isn't on many's radar, but he's been one of the worst HC's in the league since he took over, and even national analysts have begun to realize that his "offense" is stale, easy to beat, and isn't revolutionizing anything.