Continuity mistake: It is way obvious during the first Gramercy Riffs scene (over who killed Cyrus) that the lights reflecting in the Riff leader's sunglasses are location camera lights, as the warehouse has only track lighting.
Visible crew/equipment: The first time we see the Riffs leader address the Riff soldiers, when he says "who are The Warriors?" you can see the boom microphone reflected in his sunglasses. (00:19:28)
Continuity mistake: Snow's afro changes length throughout the movie. In the beginning it's medium length, when they fight the Punks later in the movie his afro is longer.
Continuity mistake: Rembrandt's hair constantly changes throughout the movie from fluffy to a more cut style.
Continuity mistake: The gang members' shadows during the Coney Island scene change from shot to shot. In some shots they are to the side of the actors and in others behind them.
Answer: There was a truce, but just in case you want different members in different parts of the crowd to see all angels and all exits in case of something. You plan if something goes wrong where everybody will be.