Narkissos,
You make a point frequently understood in ancient mythology: that there are sometimes divergent alternative versions of stories which the listener/reader is expected to hold in place without a problem: consider the Library of Apollodorus, where often it will be written, "so-and-so said this happened, but another wrote that this happened (to Achilles, Helen, Heracles, etc.)" Which version is correct? How can they be placed adjacent to each other and still all held as credible? Apparently the Talmudic commentaries entertained the same device: where there were stories with hiatus or seemingly incomprehensible details, additional possibilities were supplied by way of explanation. We recently considered the one about altering the ultimate destiny of Jephthah's daughter, and it was Rabbi Chimchi c. 1200 CE who proposed that it was temple duty and not sacirifce which was her end. I recall reading the story that in fact Abraham did sacrifice Isaac, but that he was immediately resurrected, or, alternately, that the name of the sheep sacrificed was in fact Isaac.
The proposed idea behind the maintenance of competing stories in the text notwithstanding apparent divergence and purported contradiction emphasizes the primacy of the text, that no part of the sacred account be lost, even if they, taken alongside each other, don't seem to agree. Joshua 1-12 seems to suggest a complete takeover of the land, but Joshua 13 has Yahweh rattling off all the places which remain to be conquered. Evidently these come from competing traditions of the infiltration of Canaan (which is all fiction, I agree) but it remains that both versions stand in the text right next to each other.
One of the strange things that happens to so many when reading the Biblical texts is that critical analysis goes right out the door, as if its wrong to challenge the text to make sense and be coherent. Accuracy probably wasn't the biggest deal in the world (but it is sure is to WT ironically, now isn't it?) in ancient times, so much as interactive responses to multivalent approaches.
Euripides