The name of our current epistle is most likely equivalent to the Hebrew name Jacob, though there is still some debate over this fact.  Despite the details surrounding the issue, James does seem to have been understood as meaning Jacob at the time of translating the Scripture into English, but if I am incorrect, I still see no problem in at least including the question for the sake of being aware of the topic.

    As we swiftly move away from that one, who is the brother of James, and therefore the half-brother of Jesus, that wrote another book of the Bible?

-There is no other brother-