Luffy as a 3.5 char and wisdom

[Calthropstu]

I was running a mental exercise trying to stat out random movie and anime characters and I thought of one piece and luffy.
Luffy is an interesting case for mental stats. He obviously has a very high charisma and is not the most intelligent guy around... but his wisdom is difficult to pinpoint.
On one hand, he displays an impetuousness that gets him into trouble. He has a hard time detecting deception, and he often fails at common sense.
His perception is all over the map. Sometimes he notices the smallest things, and other times he is fooled by stupid camoflauge and terrible disguises.
Other times, he makes decisions which can only be described as brilliant such as putting the skeleton on the crew.
If you were to stat his wisdom, where would you put it?

[Grod_The_Giant]

Low, but sometimes gets lucky?

(And, I'm guessing, has something like Force of Personality to keep his Will saves high)

[Calthropstu]

Low, but sometimes gets lucky?

(And, I'm guessing, has something like Force of Personality to keep his Will saves high)

His will save is actually terrible. Which leads me to believe he has a low wisdom score. He falls for every mental attack used on him.
Unless his friends are in danger. Then nothing can change his course.

Maybe something like a low wisdom score, but when his friends are in danger it gets a huge boost... something akin to a barbarian rage power.