some Itachi fanboys think Itachi alone can defeat Pain lmaoThere are power tiers to this. Deva Path alone (not Nagato himself) and without the 5 is stronger than all of the Akatsuki. Itachi, 3rd strongest member, is on the same tier as Animal path. It's really obvious Kishi made the power gap between Nagato & Obito and the rest of Akatsuki too humongous to possibly comprehend.
So even if added other Akatsuki members to this, the outcome remains the same: Pain wins low difficulty.