Your Sola Scriptura “grounds” argument is a fail.
Catholics agree with Protestants that Scripture is a “standard of truth”—even the preeminent one—but not in a sense that rules out the binding authority of authentic apostolic Tradition and the Church. The Bible doesn’t teach that.
www.catholic.com
The spoken Word of God comes from the same divine wellspring as the written Word of God. It is not an add-on .But don't take my word for it. Go to any Bible search engine and key in "Word of God" and see for yourself.
2 Timothy 3
[14] But as for you, continue in what you have learned and have firmly believed,
(Tradition)
knowing from whom you learned it
(Magisterium)
[15] and how from childhood you have been acquainted with the sacred writings which are able to instruct you for salvation through faith in Christ Jesus.
(Scriptures)
[16] All scripture is inspired by God and profitable for teaching, for reproof, for correction, and for training in righteousness,
[17] that the man of God may be complete, equipped for every good work.
Note verse 14-15. It admonishes Timothy to do three things:
- Remember what you have learned and firmly believed (Tradition)
- Know from whom you learned it (Magisterium)
- Know you have the Scriptures
The Bible on St. Paul's list comes in third, not first. He actually gives here the traditional Catholic teaching on the three sources of sound teaching.
In verse 15 he goes into an excursus on the Bible. This brief excursus emphasizes the value of the Bible and recommends a fourfold method of exegesis. This verse was used in the pre-Reformation Church as a proof text for the Quadriga which was the standard Catholic approach to the Bible.
Still taught today. The Quadriga method used the following four categories:
- Literal/Literary (teaching) - the text as it is written
- Analogical (reproof) - matters of faith
- Anagogical (correction) - matters of hope/prophecy
- Moral (training in righteousness) - matters of charity
The analogical, anagogical and moral senses of the Bible were known collectively as the spiritual senses.
The 'reformers' rejected the BIBLICAL fourfold method of exegesis in favor of a more literal approach, and ignored 2 Tim 3:16!!!
Taken does the same thing while quoting it at the same time.