The older work (NBD) noted some of the same evidence – for example that Joshua was not always noted with Caleb in the story of the Spies in the Land, or the difference between the goal of conquest and it’s completion in Joshua. The Older work operated from an assumption of accuracy of the Biblical Text and found ways to explain the evidence of “conflict” in the light of the purpose of the author – to show that the people fell short of the ideal. God acted through great events and through imperfect people. We should heed this word.
The newer work (DOT) took these as evidence of multiple and contradictory sources that were not harmonized within the text, nor really capable of being harmonized. It did not grant the Biblical text the assumption of historical accuracy, but on the basis of historical studies and attempts at recreating of the events of the Exodus came up with a very different view. It holds that there was no conquest as an event, but at best a gradual immigration of outsiders over time who were part of a transition in the culture and economy of the land. The Story of Israel evolved historically as well as textually over time. We should read this word carefully.
Both works are from Inter Varsity Press and try to integrate Scripture with historical background. Yet they show two very different views of the text.
I recall debates in the 70s over inerrancy and limited inerrancy which in my reading boiled down to this: inerrancy is deduced from the truth of God and the evidence is arranged in that light. Limited inerrancy found out it was very hard to prove that there are no errors and did not feel right in reconciling things like rabbits chewing cud or historical details that differed between two biblical sources. Inerrancy is confessional and deductive. Limited Inerrancy is inductive and inconclusive by nature.
What we bring to the text makes a great deal of difference in how we see the text.