Folks who say Scripture blew it, are of course, blowing it.
But most of the time it is readers blowing interpretation of Scripture.
My knowledge of the Acts 2:38 people, is that they are Oneness, as you say, in that the Son is the Father, and the Father is the Son, and there is only One person in the Godhead. And so, you come to Acts 2:38, and therefore make it the necessary blueprint of recital at baptism in order to be saved.
1. Oneness is false doctrine:
And the glory which thou gavest me I have given them; that they may be one, even as we are one. (John 17)
If the Father is the Son, and the Son is the Father, then for us to be one even as They are One, then I would have to be you, and you would have to be me, etc...
There would be no distinction of persons and souls in the body of Christ, even as there is supposedly no distinction of Persons in the Godhead.
And so, Scriptural oneness is that of perfect unity, not of being one and the same person.
2. Acts 2:38 is one among several Scriptures teaching baptism in Christ: baptizing in the name of the Lord, in the name of the Lord Jesus, in the name of the Father, Son, and Holy Ghost.
The last one is where you apply Oneness, and so insist the name of all three is Jesus Christ.
Which may indeed be true, since like Father, like Son, and so the Father giving His personal name to His onlybegotten and beloved Son.
3. But Baptism does not necessarily save, nor is it necessary to be saved.
Without faith, baptism, even as circumcision, is of none effect, and by faith we are saved through grace with confession of the Lord Jesus.
Baptism is a 1st principle of the doctrine of Christ, for them that believe and are saved by grace through confession of faith.
We are not saved by grace through faith and baptism.
4. Therefore, them that refuse to be outwardly baptised acknowledge their own unbelief and shame of Christ, but to judge salvation in others by whether they are baptized upon a certain formula of recited words is false accusation, being contrary to all Scripture of God about necessary faith:
But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking.
Likewise, vain repetition at baptism.
Scripture doesn't record anything said, when Stephen baptized the Ethiopian. If a formula of words must be exactly repeated, in order for baptism to be honored by God, then Scripture would most certainly repeat the formula itself.
'In the name of the Lord' first and foremost means with His authority, even if His name is not spoken at the time:
And whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him.
We are to do all things in the name of the Lord, by faith of the Lord Jesus, not by speaking His name whenever we do something, or wherever we go. That would be vain repetition indeed.
And so, those who refuse baptism, acknowledge unbelief and shame, but those not baptized to a particular formula are saved by confession of faith in Jesus, whether before or during baptism in water.