This is an interesting perspective. Let me think on it a bit before I try and respond to this post.
Some other thoughts - so what became of those that James was writing to?
Eventually, they simply died off, not having receiving their promise (until their resurrection).
In other words, they were Messianic, Law keeping Jews, Matt. 23:1,2, Acts 21:20, etc.
In contrast to those formerly lost Jews and Gentiles saved into the Body through Paul's ministry, Acts 21:21, after Paul was saved and commissioned, Acts 9:15, etc.
Question: If those Messianic Jews were not keeping the Law, as reminded to in Matt. 23:1,2, then why was the need to both require that Gentiles submit to Circumcision and keep the Law, even brought up, to begin with, Acts 15?
In this, I find today's Messianic Movement fascinating.
They rightly discern that those Believers of that assembly at Pentecost in Jerusalem had been Law keeping Messianics.
Plenty of the passages show that to be the case.
Matthew 24:20 But pray ye that your flight be not in the winter, neither ON THE SABBATH DAY: 24:21 For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.
Leviticus 23:16 Even unto the morrow after the seventh SABBATH shall ye number FIFTY days; and ye shall offer a new meat offering unto the LORD.
A reference to THEIR Feast of Pentecost, under THEIR Law...
Acts 1:12 Then returned they unto Jerusalem from the mount called Olivet, which is from Jerusalem A SABBATH DAY's journey.
Acts 2:1 And when the day of Pentecost was fully come, they were all with one accord in one place.
And so on, the witness of this is there...
At the same time, today's Messianics fail to discern that all that and its Prophesied hope, was put on hold, Romans 9-11, 2 Peter 3.
They fail to note that starting with Paul, both lost Jews and Gentiles had to come to Christ as Gentiles, Romans 4, Galatians 3.
Which is still the case today.
Meaning that today's Messianics are sort of like Apollos, in Acts l8, in their case, they only know Pentecost, they do not recognize that things changed with God's saving Paul and sending him to both without distinction.
For actually, they are in the Body, having been saved this side of Paul.
The result being that their rapidly growing group in Israel (they now number in the thousands, in Israel, alone) will have left a sizable witness of Christ to Unbelieving Israelites left behind upon the Body's catching away, prior to Israel's Prophesied Day of Wrath, followed by their Prophesied Blessing, Isaiah 66; Romans 11:25-29, etc.
Nehemiah 8:8