That standard for success or failure is so absurd its a joke. Like the majority of this thread. Realistically no one we appoint will be better than Pep or Klopp, so should we just carry on with Ralf as anyone else is going to fail by the standard that they won't win the CL and won't beat City to the title immediately?
It's a mixture of potential and avoiding risk.
Ten Hag has easily the highest potential. He's doing outstanding things with Ajax, playing fantastic football, and has done so for multiple years and rebuilt them to keep succeeding after stars were poached. The league performances are ridiculously dominant, but it's the CL performances that make people take notice and how they are punching above their weight yet again. Will be interesting to see just how far they can go.
Pochettino vs Rangnick... Well honestly, I don't think Pochettino has a higher potential with United. And that's important when you are competing with Klopp and Pep and Tuchel and Conte. What use is it getting someone who will be the 5th best manager in the league, quite a distance off the top 4 managers? We know what Pochettino's level is. We know his weaknesses too. We know he regularly has discarded the cup competitions, which nobody can say they like. People will have varying opinions over their style of football, but to me personally I'm not much of a fan. It's based on high energy and "underdog" style football, not one that is set out to dominate every game. Right away that leads to a lower ceiling than otherwise. His lack of tangible success, this far into his career with the teams he's managed, is a black mark though I agree there is loads of variance there that it is unfair to hold it against him too much. But that's why I point to his disdain toward all the cup competitions as a negative, as he is shooting himself in the foot. A general attitude from his teams when things aren't going their way, they become incredible dirty and whiny. Don't like that. His squad building, he has a long time to build a better midfield group at Spurs and I just don't think he knew how to improve it/get it better than a workmanlike midfield.
i just look at Pochettino and think he's a CL qualification chasing manager, and nothing more. He's a Spurs level manager, not a title challenging or winning manager. He's good at getting the underdog to overperform, but can't get a big team to be the top, dominant team. That's arguably a harder step than getting a smaller team to overperform with underdog tactics. We know what he is, and when we have a chance at the highest potential manager not at a major club already, settling for a limited manager who won't give us a potential advantage over other clubs is just deflating.