Naruto acting rediculously dumb is ooc.
Is Actually has a name PIS- plot induced stupidity.
Basically, just like how characters eyes pop out, they shrink, their heads throw big, etc... Doesnot mean we take it literally.
It is obvious that the few instances (3 or 4) of Naruto's extreme stupidity is simply there for comedic effect.
It's similar to madaras peeimg gag and Hashirama depression gag.
Manga are full of them. Every character in one piece has a rediculous gag.
If you can't reason through pure comedic plot devices then you should not be reading naruto, as it is too complicated for you to understand.
The target audience for naruto is 12-17 year old kids. Obviously, kishi add points irrvelent to plot or character development, in orde to appeal to his genre.