Answer

A good question. I don’t know. But atheists infer from this that the Torah is probably an invention and was not given to us from Heaven. In my opinion, that is not the correct conclusion, even though the question is a good one. I reach the conclusion that the Torah is from Sinai not because of its impressive content. It really is not impressive. Rather, because of a combination of philosophy (which proves the existence of God), and considerations that lead from that to the need for Him to reveal Himself and tell us what He wants from us, together with the tradition that has reached us and tells us that He indeed revealed Himself. After I reached the conclusion that there is a God and that He revealed Himself, I believe the tradition that transmitted to me the Torah that was given by Him. At that point I ask questions about the content of the Torah and remain with the matter unresolved, but that does not cause me to retreat from the earlier conclusions, because they are based on good arguments.
I have often given a parable for this, that of the broken clock. Paley argued that if we see a watch lying on the ground, we would not conclude that it came into being on its own spontaneously, but that someone made it. Why? Because it appears very complex, and it is not plausible that it just came about that way. What would you say if I discovered a watch that is ten minutes slow? I would have a difficulty with the watchmaker who made it (why not make an accurate watch?), and my conclusion would be that this watchmaker’s mind is built differently from mine. And still, there is a watchmaker who made the watch, because it is not plausible that it came into being by itself. In short, a difficulty does not always topple your assumption. It depends on how much confidence you have in that assumption (how clear it is to you that the watch was made by a watchmaker).
It should be remembered that what I’m saying applies even to a human watchmaker. But the ‘watchmaker’ we are talking about here is God. His mind is certainly very different from ours (that is clear to me even before the questions you raised), and therefore with regard to Him I do not even expect to understand what His policy is and why He did things one way or another. It is quite clear to me a priori that the watches He made that I find will not seem logical to me. So here the difficulty is not even all that strong.
Therefore, regarding the questions you raised, I remain with the matter unresolved (and I have quite a few more unresolved questions for you about the Bible. That is why I do not engage in it). But that does not really affect my theological and religious conclusions.