The average tenure for an NCAA coach is 3.8 years, and that's including the huge successes who stick around for a long time. Take them out, and coaches last about 3 years. They either get fired, or they get hired away. You're theory about continuity hires vs. rebuild hires is probably true if you're talking about a school that's completely apathetic about football, like KU, but it isn't true for any school that wants to be competitive (I can list off about 10 colleges off of the top of my head - who do you have in mind?). Look at our own history. Did GRob get a 5 year blank check? Did SS? 5 years was the norm 30-40 years ago, but times have changes. 68% of coaches don't make it 5 years.
As for recruiting, I'll admit I like this class, and I like that we have a ~50 ranking with a small class (vs an anomaly where we have a billion scholarships for whatever reason), but our ranking has been extremely consistent since the 2012 season where Scott put took over a Marrone recruiting class at the last minute. We were bouncing around the 50's, and now we're in the low 50's. It's not like he signed a to 20 recruiting class.
"Dino has already had 2 statement wins..."
The flip to that is we also have 2 4-8 seasons, and in this hypothetical, we'd be looking at a 3rd in a row. What good is a signature win if all you do is finish 4-8?
"There are only 2 scenarios where Dino doesn't get AT LEAST 4 years here"
Nobody (at least not me) said that he wouldn't get 4 years. Either he gets a bowl this year, or he's on the hot seat for the next season and has to wow.
"...thankfully Syverud and Wildhack make those hiring and firing decisions, and not fans"
"Thankfully" is a strong word. SU FB has a long and storied history of shooting itself in its foot at the hands of the Chancellor and the Athletic Director. Additionally, you have no insights into their opinion. You're just projecting your own wishes into what they might do, and writing it off as fact to make yourself feel relieved. Admittedly, I don't have any special insights, either, but our past actions and actions of other similar programs are consistent w/ my beliefs.