Ah, but we already have word from the Bible that the Pharisees, among others, used tradition to make the scriptures of none effect, as has the Catholic church - to whit, Mary was perpetually a virgin after the birth of Jesus. That 'tradition' was baptized into Doctrine and thus we have both tradition and doctrine in a single belief that is contrary to scripture. As we can plainly see that Jesus had not only 4 brothers; but sisters as well.
Not only does your logic fail you; but, so too does your church. And their apologetics. The very apologetics in logic they have used to prop up all the other 'traditions' and 'doctrines' they claim are inerrant and not contradictory. Don't close your eyes to it. And if it confuses you, pray to God in Jesus name to clear the confusion that you may see it clearly. Nobody here wants to confuse you; so, take the time to consider it and pray about it. The goal is truth. Will you believe what the scripture says?
Havoc, in Deuteronomy, God gave men authority to interpret the Law. Jesus himself acknowledged the authority of the Pharisees to interpret the Law.
Please keep in mind too what I have pointed out previously: that the Pharisees were not a monolithic group. The Shammaites were much more 'rigid' and 'legalistic', and likely were the group that drew Jesus's ire. On the other hand, Jesus had a great deal in common with the Hillelites.