If I may ask, Dimitris, why did you feel like you needed to know the reason for the talking animals earlier?

Talking animals are a fairly common idea. I think the number of cultures that tell stories with talking animals is larger than the number of cultures that don't. And there are plenty of other fantastical creatures in Narnia like fauns, dryads, gods, etc.
I really can't understand the argument "None of the children knew who Aslan was, any more than you do". If we look at it in a strictly grammatically sight then:any more than you do = children knew ≤ than us. But "any more than you do" does not imply that we do not know anything (about Aslan)!
Well, the children really don't know anything about Aslan at all. They hadn't spent much time in Narnia. But if the reader is expected to have read
The Magician's Nephew, they do know something about Aslan. (They don't everything but they do know a good bit more than the Pevensies.)
I agree though that this disconnect by itself isn't an unanswerable argument in favor of LWW going before MN. However it is part of the larger argument which is that LWW is written and like the first book in a series and MN is written like a prequel. C.S. Lewis introduces the story by saying that it explains "how all the comings and goings between our own world and the land of Narnia first began." This clearly implies that the reader knows-or has had the opportunity to know what Narnia is. (Note that for the Radio Theatre adaptations, which were released in chronological order, this line was changed to "a land called Narnia.") It also says that Digory "became the famous Professor Kirke who comes into other books." It doesn't say the adult Digory
may come into other stories, the way Lewis says he
may write how the Lone Islands became part of Narnia in VDT. It's clearly implying that those other stories have already been told. (OK, I'll admit that last bit is a little pedantic.

)
The ending of MN also leads into the ending of the next chronological story in a way none of the other endings do. "(Digory) had part of the timber made into a wardrobe, which he put in his big house in the country. And though he himself did not discover the magical properties of that wardrobe, someone else did. That was the beginning of all the comings and goings between Narnia and our world,
which you can read of in other books." The Voyage of the Dawn Treader, for example, doesn't end with "Everyone kept saying how Eustace had changed for the better. One of those people was a schoolmate of his called Jill Pole. And that was how she ended up returning to Narnia with Eustace one day." This ending sticks out like a sore thumb unless we assume the book's supposed to be a prequel.
I'm sorry if I seem intolerant of anyone who likes chronological order. It just takes a lot of words to explain this opinion so I risk coming across as fanatical.

I've never seen the books as being little connected stories, not one big story, so it never really bugged me if they jump around in a timeline or if characters show up in one who don't show up in others. And I don't see any reason to believe Lewis had a problem with that either.
For better or worse-for who knows what may unfold from a chrysalis?-hope was left behind.
-The God Beneath the Sea by Leon Garfield & Edward Blishen