EEPW The four clubs you mention above have all got through a bunch of managers getting to where they are now over a good few years. Two of the three getting relegated this season have got through at least 3 managers thus far. Ipswich have stuck with theirs and probably show the best promise, but their squad was mostly inherited from league 1 and are clearly not good enough. You can argue that leicester were unlucky losing Maresca, but he's hardly set the world on fire given the squad and resources he inherited at Chelsea - would he have kept Leicester up given the aging squad they have (Vardy could probably get a season ticket for OMJ he's that old)? Debateable, and probably one of the reasons he offed.
Farke has already show his ability to build a decent squad in the Championship - he's had to do it twice with Leeds. I have faith he can do the same for the prem - difference between us and Norwich is that Red Bull/49ers have some muscle and clever accountants that can make the difference whereas Norwich had a menopausal tv cook.
Anyone you bring in now has to get up to speed with the current squad and culture, set up his own team and has to deal with the dickhead fans as well. Farke already has his stamp on the squad and will be more than aware of the pressures and needs to strengthen. He's actually already said he wanted to strengthen in January but in depth analysis showed it wasn't worth it at such a late stage, so he and the 49ers have shown them selves to be pragmatic. Now he's got a (relatively) clean slate. FFS let's give him a chance before pressing the Marsch/who/Fat Sam button.