No Naruto is not "intelegent" nor was he "pancaking" in the Nagato fight.
He is smart though, I would put him in the slightly above average intelligence with people like; Kisame, Kimimaro, Baki, etc. Just not "extremely intelligent". He'll keep getting smarter tho, plus Kurama will probably end up being his "brain" while Naruto is the "vessel"; meaning Kurama will help him figure out stuff.
But in the Nagato fight, even he was saying it was a blonde moment. But it doesn't mean he is stupid, everyone besides Shino, Orochimaru, Sheldon Cooper, Chuck Norris, and Nara clan members makes mistakes.
Battle strategy tho, he is much higher than slightly above average, which is what you're mostly addressing. I'm saying that I believe he's slightly above average in intelligence in book smarts as well.