The problem is with the approach to these texts. I recently heard a convincing argument that the slaughter of the Caananites is myth in every sense of the word. [I.e. it didn’t happen, yet it has its uses as part of the historical record for the sake of those who must learn from it.] Bill Morrow from Queen’s University made the presentation. First it’s important to note that the slaughter of the Caananites was not swift and complete as portrayed in Joshua. (There are texts that indicate that the ‘conquest’ was gradual not immediate.) Then he applied principles of post-colonial theory to show the need to create such a myth for some purpose I forget. But the theory seemed to me to apply quite well. I don’t know if his presentation is online – but I suspect there will be a book at some point. That doesn’t mean that the texts in question do not have possible applications. Sorry I can’t be more specific in such a short comment.
The psalms and the prophets prohibit us from taking violence into our own hands, individually or together. So how can the violence we do to each other (and Christianity is replete with examples) be used by God to teach us not to do the same? We are slow learners. The NT confirms that our will to power is contrary to the Gospel (the NT or OT Gospel).
That NT teachers argue over interpretation is yet another example of non-Gospel behaviour. That’s why I no longer read these folks. I read their predecessors and have to agree to disagree on some things without I hope being too disagreeable.