Most scholars agree that the book of Joshua holds little of historical value. The book's origin is usually dated to a time far removed from the times it depicts, and its intention linked with a theological scheme in which Israel and her leaders are judged by their obedience to the teachings and laws (the covenant) set down in the book of Deuteronomy, rather than as history in the modern sense. The story of Jericho, and the conquest generally, probably represents the nationalist propaganda of the kings of Judah and their claims to the territory of the Kingdom of Israel after 722 BCE; these chapters were later incorporated into an early form of Joshua written late in the reign of king Josiah (reigned 640–609 BCE), and the book was revised and completed after the fall of Jerusalem to the Babylonians in 586, and possibly after the return from the Babylonian exile in 538. The combination of archaeological evidence and analysis of the composition history and theological purposes of the Book of Joshua led archaeologist William G. Dever to deem the biblical story of the fall of Jericho as "[not] founded on genuine historical sources" and "invented out of whole cloth."
And speaking about his brilliance, what he accomplished in Ai and Gibeon in latter campaign, is just absolutely brilliant and BRUTAL as well. And yes, he did it all without my favorite weapon in warfare, artillery unit.