Obito just confirmed in this chapter that the Uzumaki are in fact more powerful than the Uchija when he confessed to Sakura that he was not able to control both of madara's rinegan eyes wihtout losting himself to such power. so now we can see why madara chose Nagato, an Uzumaki, and not Obito for his original plan. in conclusion, I guess, perhaps Nagato could have easily defeated ITachi if they ever fighted 