Sky are like a juggernaut. Stand in its way and you generally get flattened. Think your analysis could very well pan out. Yates looked nailed on for the Giro until that 3rd week when the legs just said "no" and Froome stepped up. G has won some seriously important stage races, but never been in with a shout of a Grand Tour. That 3rd week separates the wheat from the chaff. Not sure Dumoulin will make such big gains in the TT; he'll have a lot of miles in those legs. What will be very interesting is if Froome goes on the attack in the Pyrenees and G takes off after him.
By the way, distinctly unimpressed with Wiggins yesterday. Ducked all the serious questions.