Agreed. It's what I've been reading about how he was at RB, though, that's giving me pause. He did have them performing at a high level, but had he stayed more than 2 years, would that have been the case in years 3, 4, etc.? Would he have ended alienating his players? I don't know, I have a nagging (yeah, I know) feeling about this one.
The one that fills me with confidence is Gallardo. He was at River for 8 years. Had success in the beginning, had success in the middle, and had success at the end of his reign there. No blowups and his players loved him. If it's not him, I'd like someone like that. Don't know who the European version of Gallardo is, but I know it's not Nagelsmann.