On the P2 Naruto upgrade thread there's a discussion about multiple Rasengans adding up for an increase in AP. Rasengan Barrage is specifically noted in the databooks for being 2x stronger than normal. Since it's just.. Two Rasengans. Go figure. But if we accept it might open the potential for abuse. If we accept that stacking attacks multiple times over via clone spamming is an increase in AP, Naruto's AP in VS matches would be a LOT higher than what's listed on his profile.
Say SPSM Naruto is matched against a character equal to him in AP. If we say Rasenshuriken > Rasengan Barrage which is 2x normal Rasengan, Naruto could bust out the Super Tailed Beast Rasenshuriken (9 Rasenshurikens basically) and just immediately one shot his opponent with an 18x advantage?
And if we consider Naruto's Asura Avatar to be much more powerful than Super Tailed Beast Rasenshuriken. And then said Asura Avatar makes two big ass Rasenshurikens, each being 2x the power of Asura Avatar. We suddenly end up with Six Paths: Ultra Big Ball Rasenshuriken being at least 72x stronger than SPSM Naruto. And all of a sudden Naruto is 5-A.