You're missing the point...
The commandment is not for the salvation of the person being baptized, but for those who look on, that they come to understanding by that which is revealed of God through manifestation in the world. Likewise, we are not saved by Christ's death in the flesh, but by His life in the spirit.
Your presentation is incomplete without carrying it through to include the meaning behind the manifestation as being the end of the matter and the point. The foreshadowing manifestation is not the point. For this reason John said, "He must increase, but I must decrease." "He" being Christ, the Last, the life-giving Spirit. Baptism by water is for the First, but the Holy Spirit is for the Last.
I do not see where you are getting the idea that the command to be baptized is for "those who look on". In Acts 2:38 the command to be baptized is for those who are lost in their sins and therefore the lost are commanded to be baptized "for the remission of sins".
Eph 4:5 today there is just "one baptism" that is in effect, not two. And that one baptism is the baptism of Christ's great commission that is commanded to all men, that saves. NO one today is baptized with the Holy Spirit, no one today was ever promised this baptism and this baptism was a prophecy of Joel that the Lord fulfilled in Acts 2 and Acts 10 whereby this baptism has ceased, ended.