You missed the single most important passage in Josephus which shows that the brother of "Y" does not always mean "Y" was human.
That passage is irrelevant. I was looking at expansions of proper names specifying a fraternal relationship, in a manner similar to patronymic names (I suppose I could call them fraternonymic names), to find parallels to the construction used in Gal. 1:19. That passage in Josephus is not an example of that. My only point, irrespective of any other facts, is that the expression that Paul uses otherwise pertains to literal family relationships, not a spiritual sense of a brotherhood (as when Paul refers to other Christians as "our dear brothers").
As for the emperor, who was worshipped as a living god in the Roman Empire, he may well have construed himself as having a familial relationship with the gods.
It is a failure of logic to assume the "Lord Jesus" was human in Galatians. <snip>
1. Galatians 1.1--The Lord Jesus was NOT a man.
No, it is a failure of reading comprehension to miss that Paul believed that Jesus was born and died a man but who was glorified in the resurrection as the spiritual and powerful Son of God. As stated in Romans 1:3-4, "his Son was a descendent of David according to the flesh [ZOMG HE WAS A HUMAN!!!] who through the Spirit of holiness was appointed the Son of God in power by his resurrection from the dead: Jesus Christ our Lord." Thus Paul had zero problem referring to Jesus as a man: "...how much more did God's grace and the gift that came by he grace of the one man, Jesus Christ, overflow to the many" (5:15), "so through the obedience of one man the many were made righteous" (5:19), "Since death came from a man, the resurrection of the dead comes through a man" (1 Cor. 15:21), "being found in appearance a man, he humbled himself by becoming obedient in death" (Phil. 2:8). The point in Gal. 1:1 wasn't that Jesus wasn't ever a man; it was that Paul's mission was divinely authorized...he was not merely sent by men, like those sent from James to Antioch (Gal. 2:12), but directly by Jesus through divine revelation (1:11-12, 16, 2:2).
The conception of Jesus in Galatians is parallel to that in Romans. He presents Jesus first as a man born in the flesh: "God sent his Son, born of a woman, born under the law, to redeem those under the law, that we might receive adoption to sonship." (Gal. 4:4-5). Then he was crucified and died (2:21, 3:13), which redeemed the faithful from the curse of the law, but God "raised him from the dead" (1:1), who now in the spiritual sphere guides Paul through revelation (1:12, 16), and whose Spirit God sends to the believers (4:6). The sonship that Christians receive parallels the sonship that Jesus receives in the resurrection in Romans 1.
The point is driven home by the Hagar analogy in chapter 4. Just as Jesus was "born of a woman, born under the curse" (4:4), so too the believers born as slaves through Hagar, "born according to the flesh" (4:23, 29). The adoption to sonship however gives the believers their inheritance and freedom from slavery from the law. They are "born as the result of a promise" (4:23), their mother is "the Jerusalem that is above" (4:26), they are "born by the power of the Spirit" (wording very similar to Romans 1:3-4 about Jesus being appointed the Son in power by the Spirit of holiness). So this parallelism between Christ and the believers works because Jesus was similarly born in the flesh, born under the law, subject to its curses (see the previous chapter about the law cursing him in death), and glorified to sonship in the power of the Spirit. So Paul says "brothers and sisters, we are not children of the slave woman, but of the free woman" (4:31). This does not mean that Paul and other Christians were never really born in the flesh and were always indwelled by the Spirit; they had a change of circumstance, their bondage to law by being born in the flesh no longer counts, they have transcended it thanks to Christ. Thus, as Paul wrote in the previous chapter, "there is neither Jew nor Gentile, neither slave nor free, nor is there male and female" (3:28); these divisions are based on fleshly criteria that no longer matter. So Paul's emphasis on both Jesus and the faithful as being born in the flesh under the law is critical to the whole point of the letter. Why? The whole point of the letter is to argue against the continued practice of circumcision. The dispute about circumcision is what occasioned the letter. That is why Paul makes a point about mentioning Jesus being born a human being under the law; circumcision more than any other portion of the law is concerned with the flesh and its divisions (such as Jew and Gentile, male and female). Paul says in essence: It doesn't matter anymore if you have been adopted as God's child.