question

peace,
I saw a certain book in which there are all kinds of notes on the differences between the Rambam's Book of Mitzvot and the Strong Hand, and then the book actually gives all kinds of theories as to why there are differences.
The question is, is it true that we need to look for differences and give them reasons? Are the differences perhaps due to all sorts of technical reasons that have nothing to do with deep things of various kinds?
And a question on top of that – the various theories in the book seemed to me at least quite imaginary (here he meant this kind of holiness, here he meant another kind of holiness. Here he spoke about the mitzvah from the perspective of the people of Israel, here he spoke about the mitzvah from the perspective of God, blessed be He, and so on, all sorts of ways to reconcile various differences). Am I right in my feeling or are there really and truly these deep reasons?
Thank you very much.