He was the king of Asgard. You don't become the King of Asgard (Even if you have birthright) with little intelligence. Thor may not be knowledgeable with books, or know the history of the human race, but from a non human perspective, he is quite intelligent, if nothing else, of average intelligence of his kind.
As said, he is incredibly well versed in military strategy, combat situations, and how to negotiate (yes, even without violence) peace.
"book smart" and "science smart" does not apply to every being in the Multiverses' intelligence scale
While I like that they are using the Ultimate look, I would rather they give him the purple arrow version (New Ultimates). I can just see Young Justice fans calling him a ripoff of Red Arrow, and now is the time to distinguish them