Some of what you say is not accurate; it was the disciples of John in view in Acts 19 and not normative.
All Jews everywhere were baptized by John, Mark 1:4-5
John came baptizing in the wilderness and preaching a baptism of repentance for the remission of sins.
Then ALL the land of Judea and those from Jerusalem went out to him, and were all baptized by him in the Jordan river, confessing their sins.
Only the few Jews John rebuked were not baptized. The Ephesians in Acts 19 were faithful servants to God. This is why Apollos batized them with the baptism of John.
The problem was Jesus gospel was already in effect. John's baptism had ended.
Apollos did not know about the gispel of Jesus Christ.
This is why Paul had to teach the Ephesians in Acts 19, to believe in Jesus and be baptized for the remission of sins, Acts 2:38; Mark 16:15-16; 1Peter 3:20-21.
Notice that the Ephesians were saved BEFORE they got any power from the Holy Spirit.
This proves God does not work miracles on us through the Holy Spirit to save us.
We are saved by hearing, believing and obeying the gospel of Jesus Christ, Romans 1:16.
Acts 18:24-25
Now a certain Jew named Apollos, born at Alexandria, an eloquent man and mighty in the scriptures, came to Ephesus.
This man had been instructed in the way of the Lord; and being fervent in the spirit, he spoke and taught accurately the things of the Lord, THOUGH HE KNEW ONLY THE BAPTISM OF JOHN.
Everything I taught is scripturally correct. There is no error in what I taught you.
Apollos taught the Ephesians John's baptism during the gospel baptism of Jesus, Acts 2:38.
This is why Paul had to rebaptise them. That they believe in Jesus and His gospel. Only after their baptism
Were they saved and given miraculous gifts of the Holy Spirit.
Nowhere did the Ephesians obey a gospel of faith only and no works of obedience to God.
They were saved by the gospel of Jesus Christ that Paul preached to them, Mark 16:15-16.
Ephesians 2:8-9 is not teaching no works salvation. The Ephesians were saved by Grace, faith and obedience to the gospel, Acts 19:1-5.