What movement type indicates how units operate differently during drills?

The movement type that indicates how units operate differently during drills is supplementary command. This concept involves specific instructions that are provided to units to complement fundamental commands, allowing for the execution of movements that may be distinct or additional to the primary directive. Supplementary commands enable varying actions by different units, fostering a nuanced approach to collective movements.

In the context of military drills, these supplementary commands are vital for ensuring that different segments of a formation can respond in a coordinated yet distinct manner based on their unique operational requirements. This enhances the overall effectiveness and adaptability of units during maneuvers, ensuring that diverse formations function properly under varying scenarios.

Other options, such as simultaneous movement or independent movement, emphasize the manner in which units act either together or separately, but they do not specifically address the application of different operational instructions that vary across units, which is the core of what supplementary command achieves.