You are working hard to create a narrative so your house of cards won't fall.If you study the Greek of that text carefully in its context it indicates that the Gentiles who had clearly already been seeking to hear the gospel (Acts 13:42, 44) had assembled themselves on this subsequent day, lined themselves up (τάσσω, reflexive middle voice) to be present when it was preached, and believed when they heard it. "As many as were lined up with a view toward eternal life." This might be comparable to the crowds who used to line up at Billy Graham crusades. This understanding is also consistent with how the opposite reaction is described, the Jews who thrust the Word of God away from themselves (ἀπωθέω, reflexive middle) and "judged themselves unworthy" (κρίνω plus reflexive pronoun).
I don't expect to convince you of this interpretation, only to demonstrate that it is possible to understand Luke's words differently than you do.
The text is clear that God orchestrated who would come to listen and who would believe.
Why do you fight against God's Sovereign will being accomplished? Do you wish to have that authority for yourself?
I suggest you read what God says and believe it rather than continually looking for an alternative narrative that fits your preconceptions.