You said: "As all men start off unregenerated, for your POV to be true, nobody could repent of sin."
This statement indicates you don't know scripture or the power of God.
If you read 1 Cor. 2:14-16 carefully and with a prayerful attitude, you'd see that it says no unregenerate man can repent of sin. Certainly the Pharisees thought they did, but Jesus told them they were liars. And there will certainly be some who think they repented of sin, but Jesus said "not everyone who calls Me 'Lord' will enter the kingdom of heaven."
1 Cor. 2:14-16 implies that God must do something to a natural person to make them spiritual, which is what is described in Eph. 2:5. You yourself said that God grants repentance, which means God has to grant repentance to an individual before that individual can repent. So in effect, according to Eph. 2:8-10, all spiritual activity of anyone who believes the gospel is the gift of God, since it all must come as a whole package. Salvation is the gift of God. Grace is the gift of God. Faith is the gift of God. Repentance is the gift of God. Justification is the gift of God. Sanctification is the gift of God. It's all God's gift.
But you make justification, salvation, and the Holy Spirit a merited condition by virtue of repentance, baptism, and obedience to the NT, according to your response here.