Look at all that and Paul hadn't even written his epistles to the churches yet.I like your suggestion. But I'm amazed that you think there are multiple "plans of salvation".
So here's what you would have:
The gospel includes the grace of God.
Acts 20:24 (KJV) But none of these things move me, neither count I my life dear unto myself, so that I might finish my course with joy, and the ministry, which I have received of the Lord Jesus, to testify the gospel of the grace of God.
The gospel involves repentance. Acts 20:21 (KJV) Testifying both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ.
The church is a flock
Acts 20:28 (KJV) Take heed therefore unto yourselves, and to all the flock, over the which the Holy Ghost hath made you overseers, to feed the church of God, which he hath purchased with his own blood.
The gospel would be perverted by wolves that want to draw believers away from the truth--
Acts 20:30 (KJV) Also of your own selves shall men arise, speaking perverse things, to draw away disciples after them.
Gentiles would share an inheritance with the rest of the elect
Acts 20:32 (KJV) And now, brethren, I commend you to God, and to the word of his grace, which is able to build you up, and to give you an inheritance among all them which are sanctified.
In THE kingdom of God
Acts 20:25 (KJV) And now, behold, I know that ye all, among whom I have gone preaching the kingdom of God, shall see my face no more.
Which is what we have now. Would God only provide a single witness, when He requires at least two?
It's also interesting because it's all recorded by Luke who was a Kingdom believer.
I always marvel at Acts. It's such a period of transition.
The church is a "flock" is not really doing Paul justice, since we know the Risen Lord revealed to Paul that we are the body of Christ.
In fact, every verse up there is explained in Paul's epistles.
As far as witnesses, the risen Lord also spoke to Ananias, and, of course there is the Holy Spirit.