He's meant to be seen as a bit of a hick, even in terms of design (haramaki and booze), in my opinion. As other users have said, "street smart", with some good ideas but overall portrayed as not the brightest in the crew at all (Zoro needing a medicine for dumbasses, how Rayleigh doubted him and only him, etc.).
Anyways, you guys shouldn't make this too complicated. Not only Oda doesn't care about "multiple intelligences" (or whatever, commonly pseudoscientific approach you want to follow) but has explicitly stated that Nami was the smartest in East Blue after Beckman and that he can't decide on who was the dumbest back then because they all seemed quite stupid to him.