hate to repeat myself lol:
I just don't get it. Like I said, if you based your entire argument off of CT and it fails, what else can you say?
Itachi showed that he can think calmly in tight situations. He analyzed the situation (quicker than Shikamaru), came up with a strategy and utilized it. Followed up with another attack, sealing Nagato away forever. Face it, his genius is what won the battle. And no, not Naruto and Bee, who were being held most of the time and being scared the other half. It wasn't 3 vs. 1. The attack to the core was solely Itachi.
Could he have done it on his own? Probably. Would he take that chance? No. He's tactical. If you have it, use it.
Itachi single-handedly stopped the shared vision, the statue and sealed Nagato. All the abilities that were so debated had become mute. What more do you need to prove it. Itachi's genius combined with the powerful techniques he has makes him the stronger ninja.