Dear Halevi,
I’m only going on the great Talmedei Chachachim throughout the generations that had direct knowledge of how our Holy Torah has been preserved throughout the ages. I’m sorry to say that you are going of off an academic instruction that is full of assumption, and reliance on on discreted sources. The fact that this academy was presented centuries ago, does not make it reliable.
Both of the major figures that you are standing behind were controversial and non traditional in their day. And one of them is very responsible for the mass assimilations that overtook us, in the last two centuries. One major source that rejected that academy of thought because of what he actually knew, was the Marshal.
If you are fully aware of Jewish History [Not history of Jews.] you know exactly which topics I’m referencing. I’m not going to elaborate. If you did not yet get up to this in your own learning of gemara, do not worry about it. You can be a real gadol without ever discovering it. And I’m still an am haaretz with all my researching. The Talmedai Chachamim I spoke with at length, would probably have preferred to be discussing the shiur they gave in yeshiva with you.