Good post, I can see the thinking behind both type of options.
Pellegrini and Mourinho probably have something to prove, to the world as well as themselves, whereas the less experienced options might be better long-term options, but how long is a manager likely to be around for ? Three, maybe four years might be a fair guess ?
Its all about sustainability.
The reason we got Bobby in was hes cheap, he was young and he had room to grow, with the club, it sadly hasnt worked out, he is out his depth.
The next manager will be somebody that can get results and grow the football club on the pitch, while we grow the football club off the pitch.
Jose and Zombie would normally be out of reach, but both are "available" hence people "linking" them to us, personally I dont think we will get either of them, Jose for 1 "demands" 15m a year in wages, it would make more sense to go for a "mid tier" manager such as RDB/Cocu/Koeman/AVB and allow them to have a half arsed crack at the top 4, I say half arsed, they will be given funds in order to do it, but unlike some, I cant see us spunking a load of wedge until we have our house in order OFF the pitch.
As you say normally a manager is given a few years, unless he tanks it hard, maybe "next" time we can put the "top tier" managers such as Emery, Jose and Simeone on the list, but for now, I think those names are sadly pipe dreams.
TL;DR
Hire Frank