RE: We don’t (and shouldn’t) always take it literally.
I think the author has the right idea. Not everything in the Bible should be taken literally. Some have to be taken figuratively ( and I don’t think the author is referring to the slaughter of the Canaanites as figurative).
Many of Jesus’ sayings are clearly figurative (e.g., He is the door, He is the vine, we are the branches, etc. ).