I'm not sure our owners are that ruthless though, the media paints them that way but how have they been ruthless? If they were ruthless, they would have cut Clueless' throat sooner instead of allowing him 1 1/2 seasons of mediocrity.
I also don't agree that we've "bought the best players". We've bought some real talent but only a few of them could really be called world class upon joining the club (Aguero, maybe Yaya and Tevez). We haven't been signing the true cream of the crop like Messi, Ronaldo, Iniesta, Xavi, Fabregas, Alonso, Schweinsteiger, Ribery, and Robben. Silva and Hart have become world class players in Mancini's tenure, Silva wasn't signed as one (remember all the doubts about him?).
Mancini has done a great job of improving players on the cusp or with the potential of being something special into something special like Silva, Hart, Kompany, and Micah.