Um sorry but it is nonsense to imagine Paul simply contrasts Hebrews with Greek Hebrews
and contrary to context
Galatians 3:8–29 (LEB) — 8 And the scripture, foreseeing that God would justify the Gentiles by faith, proclaimed the good news in advance to Abraham: “In you all the nations will be blessed.” 9 So then, the ones who have faith are blessed together with Abraham who believed. 10 For as many as are of the works of the law are under a curse, for it is written, “Cursed is everyone who does not abide by all the things that are written in the book of the law to do them.” 11 Now it is clear that no one is justified in the sight of God by the law, because “the one who is righteous will live by faith.” 12 But the law is not from faith, but “the one who does these things will live by them.” 13 Christ redeemed us from the curse of the law by becoming a curse for us, because it is written, “Cursed is everyone who hangs on a tree,” 14 in order that the blessing of Abraham might come to the Gentiles in Christ Jesus, so that we might receive the promise of the Spirit through faith. 15 Brothers, I am speaking according to a human perspective. Nevertheless, when the covenant of a man has been ratified, no one declares it invalid or adds additional provisions to it. 16 Now to Abraham and to his descendant the promises were spoken. It does not say, “and to descendants,” as concerning many, but as concerning one, “and to your descendant,” who is Christ. 17 Now I am saying this: the law, that came after four hundred and thirty years, does not revoke a covenant previously ratified by God, in order to nullify the promise. 18 For if the inheritance is from the law, it is no longer from the promise, but God graciously gave it to Abraham through the promise. 19 Why then the law? It was added on account of transgressions, until the descendant should come to whom it had been promised, having been ordered through angels by the hand of a mediator. 20 Now the mediator is not for one, but God is one. 21 Therefore is the law opposed to the promises of God? May it never be! For if a law had been given that was able to give life, certainly righteousness would have been from the law. 22 But the scripture imprisoned all under sin, in order that the promise could be given by faith in Jesus Christ to those who believe. 23 But before faith came, we were detained under the law, imprisoned until the coming faith was revealed. 24 So then, the law became our guardian until Christ, in order that we could be justified by faith. 25 But after faith has come, we are no longer under a guardian. 26 For you are all sons of God through faith in Christ Jesus, 27 for as many of you as were baptized into Christ have put on Christ. 28 There is neither Jew nor Greek, there is neither slave nor free, there is neither male and female, for you are all one in Christ Jesus. 29 And if you are Christ’s, then you are descendants of Abraham, heirs according to the promise.
