Newcastle werent all but relegated, they were 2 points of 17th place but yes I get your point about qualifications.
Guardiola or Tuchel both went into teams on the up not the decline which would be our situation. And Tuchel had plenty of experience managing at lower levels both in youth and first team football didnt he?
Newcastle were doomed, yes mathematically they were close but they were completely demoralised and hopeless and clearly going down. They brought in Shearer in a desperate last bid to rally the troops and raise morale. It was an idiotic idea.
And no, Tuchel only was reserve coach before going to Mainz. There's Pál Dárdai too, who did take over a team truly in decline and that worked out too. As I said, there are plenty of examples where it didn't, it happens. And I'd argue that we aren't in decline at all, we're in the doldrums: we've got enough money to do better, we've got the players to do better, we're just bereft of organisation, ideas and inspiration.
Again, I'm not saying Unsworth is the answer, I just think people place far too much emphasis on this mythical "first team management experience" (as if saving Arseofnowhere Town from relegation into the Fray Bentos League gave any kind of transferable skills to managing a Premier League Club trying to break into the top six/five/four whatever) and far too little on knowing the team inside out and having a clear idea what to do with them.