Complex sentence: Major Armbruster suggests a test of whether Reisman's men are ready: during practice maneuvers in which Breed will be taking part, the "Dirty Dozen" will attempt to capture the Colonel's headquarters.
Split into simpler sentences: Major Armbruster suggests a test that would show whether Reisman's men are ready. During practice maneuvers in which Breed will be taking part, the "Dirty Dozen" will attempt to capture the Colonel's headquarters.