Complex sentence: The units can act in a stationary capacity as a casualty clearing station, field hospital or treatment centre or alternatively they can be used to transport multiple stretcher patients from scene to the next definitive point of care.
Split into simpler sentences: The units can act in a stationary capacity as a casualty clearing station, field hospital or treatment center. Alternatively, they can be used to transport multiple stretcher patients from scene to the next definitive point of care.