Your argument appears to want to completely dismiss oral tradition. We can never know all the teachings Jesus presented to the Apostles (or to others for that matter) just from scripture alone. Oral tradition is not a pretense for Church doctrine. This is very clear when one reads the many of writings of early Church Fathers, some of whom were taught directly by the Apostles. Some were presbyters and bishops appointed by the Apostles or were their successors.
“Oral tradition is not a pretense for Church doctrine. This is very clear when one reads the many of writings of early Church Fathers...”
I can agree that there is value in tradition that occurred up until about 100ad. If it wasn’t practiced by then, written about by then, etc., the it is suspect. In any case it isn’t inspired and authoritative. If it appeared hundreds of years later, it is bogus.