What is the focus of the poem Mulan joins the army for her father? Why is it arranged this way?

The focus is on Mulan’s preparations for war before the war and the reunion of relatives after the war, but the process and scenes of the war are not described in detail. The journey of thousands of miles and ten years of hard work are briefly described, leaving readers with a lot of room for imagination. In addition, the author's interest is not in showing the war, nor in praising Mulan's heroic behavior of galloping on the battlefield and defeating the enemy, but in the dramatic event of Mulan disguising herself as a man and joining the army in place of her father.