I realize that part of your argument is: since baptism isn’t mentioned in every setting discussing baptism then it can’t be that important. Thus if “A” and “B” are equally important to God they should be in all of the scriptures. That argument would seem to make sense except for two reasons:
1. It would make bad theology on other topics. Take the godhead for example. Does Jesus’ name show up every time God is mentioned? No. But since His name isn’t always in every text, the Jehovah Witnesses use that an excuse to deny Jesus’ divinity. The issue gets even worse when it comes to the Holy Spirit – who we KNOW is part of the Trinity – but whose name is rarely if ever used as God. I have met preachers who have denied the divinity of the Holy Spirit on that basis alone.
2. The absence of an element in a text (A or B) does not make it cease to have importance. I challenge you to go thru the book of Acts and investigate each salvation experience. Keep a record of people did when they were saved.
As you go through each salvation story, ask yourself: Did the Scripture say they “Believed” “Repented” “Confessed” “were Baptized” or “Prayed a prayer of salvation”.
What you’ll notice is
1. Faith/belief wasn’t always mentioned.
2. Repentance was mentioned only once or twice, etc.
I believe God holds all of those elements as valuable, but I’m not discouraged when they’re not mentioned in each and every text. Why? Because my intention is to take the whole of Scripture for my counsel.