This past Sunday (4/8/18), I (Carson) mentioned that I would post a couple of articles that deal with the difficult moral issues surrounding the Canaanite conquest.
First, here’s a link to a relatively brief article found in the Apologetics Study Bible by Mark Durie.
Second, if you are more into video-watching instead of article-reading, the Bible project video has a few helpful points regarding the destruction of Jericho. (And an article to boot in case you accidentally find yourself reading!)
And lastly, here’s a few thoughts of my own that might be helpful to you as we consider why God would have ordered the destruction of an entire group of people.