Chelsea were a fairly nondescript midtable club, but if i recall correctly (which is by no means guaranteed) they were more or less instantly elevated amongst the elite when the russian money arrived.
Man City took a little bit longer to get to the top, it seemed they struggled to attract big signings as quickly, and there was one more big club up there in the form of Chelsea. Of course having all that money has to tell eventually.
Newcastle are now trying to compete with Chelsea and Man City + the traditional big clubs, so it is already a more crowded scene, and at a time when even a newly promoted side can splash 100m on players and go straight back down. suspect that they may take that little bit longer to establish themselves at the top.