emery, I try to keep it simple for my mind's limitations. there were at least 2 baptisms before the command in Math:28, that of John and that of the disciples of Christ, at that time still locked in the earthly Israel kingdom hope.
Jesus commanded a baptism that seem to embrace all that and all his teachings, which had seeds of both earthly(material) and heavenly hope. (but no exclusive certainty)
Actual baptisms after pentecost varied, wether the person was Jewish, already baptized by John, by the disciples or a Gentile like Cornelius who was anointed even before his baptism.
After Cornelius (the first other sheep), there was only one anointed Christian congregation, the Israel of God. One valid baptism. all partakers. all in the New Covenant. but
within that spiritual nation where people of two destinies, according to god's choosing! for example: Peters waited - for ----New Heaven and New Earth.
There was also the SEALING of the future rulers with Christ OUT OF that congregation: starting with execution of Stephen and ending with the last martyr prior to Armageddon.;the sealing of the "axed" 144k.
I like to believe in I anointed congregation, I baptism, God (if any) looking at all that and making already described choices, sealed ones, firstfruits, heavenly rulers, temple foundations,
our trying to second - guess the creator on his part are power plays.