Tradition does count. It’s the words of Jesus passed on from person to person. How did Paul find out about Jesus appearing to 500 people at once? It’s not in any Gospel......it’s tradition. It was passed by word of mouth to Paul.
Luke 1:1-4 (NIV)
Many have undertaken to draw up an account of the things that have been fulfilled among us, just as they were handed down to us by those who from the first were eyewitnesses and servants of the word.
With this in mind, since I myself have carefully investigated everything from the beginning, I too decided to write an orderly account for you, most excellent Theophilus, so that you may know the certainty of the things you have been taught.
Your ignorance of scripture is laughable...
And which you know by what source? The Scriptures! (1Cor. 15)
And by what transcendent, testable medium did God perpetuate and preserve what He told Moses and others? (Ex. 17:14; Num. 5:23; Dt. 17:18; 31:24; The wholly inspired of God Scriptures!
Now go, write it before them in a table, and note it in a book, that it may be for the time to come for ever and ever: (Isaiah 30:8)
And on what basis were the Truth claims of Christ established upon? Scriptural substantiation in word and in power! (Jn. 5:36,39; 14:10,11; Lk. 24:44) And upon what was the veracity of the oral preaching of Paul subject to testing by? The wholly inspired of God Scriptures! (Acts 17:11)
The fact that some, and only some, of what is in Scripture was first expressed in oral form does not support a church presuming that because something else existed in oral form, does not justify a church claiming this is also Divine revelation, whether it be Mormonism or Catholicism.
And in the case of the Assumption, it lacks even early historical testimony but which Rome claims to "remember" much later.
Ratzinger writes (emp. mine), Before Mary's bodily Assumption into heaven was defined, all theological faculties in the world were consulted for their opinion. Our teachers' answer was emphatically negative . What here became evident was the one-sidedness, not only of the historical, but of the historicist method in theology. “Tradition” was identified with what could be proved on the basis of texts. Altaner, the patrologist from Wurzburg…had proven in a scientifically persuasive manner that the doctrine of Mary’s bodily Assumption into heaven was unknown before the 5C; this doctrine, therefore, he argued, could not belong to the “apostolic tradition. And this was his conclusion, which my teachers at Munich shared.
This argument is compelling if you understand “tradition” strictly as the handing down of fixed formulas and texts [or actual ancient reliable records] …But if you conceive of “tradition” as the living process whereby the Holy Spirit introduces us to the fullness of truth and teaches us how to understand what previously we could still not grasp (cf. Jn 16:12-13) [meaning grasping extraScriptural fables to make them binding doctrines], then subsequent “remembering” (cf. Jn 16:4, for instance) can come to recognize what it has not caught sight of previously [meaning the needed evidence was absent] and was already handed down in the original Word.” [via amorphous oral tradition] - J. Ratzinger, Milestones (Ignatius, n.d.), 58-59.