It's undoubted that Big Sam is the man to turn to to get a club out of the shit at the bottom of the league - done it too many times for it to be a fluke.
However, whenever he's had financial backing (Everton and Newcastle) he's bombed. I don't subscribe to the theory that his squad at Everton is weak, Jagielka was an England regular 18 months ago and could replace the hapless Williams, there's good young talent in Davies, Calvert Lewin, Holgate and Lookman alongside good solid performers like Sigurdsson, Rooney, Coleman and Walcott. He could and should be doing better there.
The problem for me is that he is a legend in his own mind and firmly believes he can manage a top club, the records suggest otherwise. It would've been interesting had he been in the England job for a length of time but his arrogance and greed put paid to that. Sadly, there will always be a large faction of football supporters who remember him for his arrogance rather than his managerial abilities.