[what's up]

Jude identifies himself the same way and adds that he is the brother of James.

Yes, but by your method of interpretation, you would have to parse this and say that Jude is not the actual brother of James, would you not?

[wagglebee]

No, they are both identified elsewhere as having the same father. It's in the links I posted, I'm going to bed.

[Zechariah11]

Remember that the New Testament was written in the precise Koine Greek, not Aramaic. Here is something which supports your view:

The Greek ADELPHOS is not contextually like the Hebrew ACH, meaning "brother" or "blood relation." ADELPHOS as used to describe Jesus' brothers, is very precise Greek and means "from the same womb." The Greek word for "cousin" ANEPSIOS and is used clearly in Colossians 4:10.