It looks like we must again make sure, before moving forward, that we all know what Tradition AKA Holy Tradition AKA Sacred Tradition--the alternative to Scripture that some churches follow--actually MEANS!
The theory in question does not deal with mere legends, opinions, folklore, or customs. The theory is that there has been a continuous body of belief in the church since the beginning that by its universality and consistency shows itself to be a second revelation from God, like the Bible. None of that has any fact behind it; its all theory.
The theory Is not mentioned or described or recommended in Scripture. And the doctrines that have been created by the institutional church(es), allegedly in accordance with Holy Tradition (as described above) do not meet the tests of universality or consistency anyway.
They have simply been simply decreed as a result of the church leadership choosing to dogmatize some idea, opinion, or other that it took a liking to. The doctrine thereafter is SAID TO have been the faith of the church from the beginning forward.