 Remaining criticisms which the defenders of the "Wuzi"'s authenticity cannot account for center on the book's description of cavalry as a major, important branch of the military.Because the use of cavalry (presumably) did not become important until the (very) late-Warring States period, the text's emphasis on cavalry implies that present editions must have been edited after Wu Qi's death (unless cavalry became important in central China much earlier than presently believed).Unless evidence is found that cavalry became important in China before c. 300 BC (the date modern scholars generally assume Cavalry became important), then either parts of the "Wuzi", or the entire text, must be attributed either to the late Warring States or the early Han dynasty.