The war that Michael the archangel wages against Satan and his angels is not just one of brute force. That kind of war would be easy for Michael.
.........There is something else involved. There is the aspect of a court trial in which Satan shows why he should keep the bodies of the Saints. A similar dispute took place when Michael contended for the body of Moses.
....................Satan takes up each case spearately and raises charges. He will fight over every single body.
..............................The accused answer and give testimony to dispute Satan's accusations.