Of course it's simplistic. A gang is made up of criminals and criminals are defined by the largest occupying gang. Gangs are like government startups if you will. They offer protection and services and represent themselves with flags and other branded accessories to distinguish themselves from competing enterprises. Fortunately in this market customer consent isn't entirely necessary. It's an industry where the market share is determined only by what you can extort or point a gun at. Taking neighboring turf is risky, but highly profitable. The higher ups will send the low ranking gangsters to serve a higher cause such as brotherhood and civility, and ultimately serve bullets to the neighboring gangsters (as identified by their distinguishable uniforms). Sure they may die, but they did it serving a greater cause. Of course, all parallels drawn here are merely coincidental.