Complex sentence: The students and troops were allocated into groups of around 20 students called a "Brigade", four or five brigades made a Troop, each Brigade had a task, some being static and others in reserve were given transport so they could rush to threatened areas.
Split into simpler sentences: The students and troops were allocated into groups of around 20 students called a "Brigade". Each Brigade had a task, some being static and others in reserve were given transport so they could rush to threatened areas.