Crash test dummies are the people who are too unambitious, stupid, impulsive or unreliable to ever be given serious responsibilities or achieving major power in a criminal organization. As a result, they are treated as totally expendable.
Middle management types are the solid earners for the organization...
The players are the top dogs. The ones who really make the power moves.
The prime examples used are the Sopranos and the Wire, but this categorization seems to be able to apply to many movies and television shows. Intuitively, it seems to apply to the hoods on the street too, but I try to avoid direct experience in that area.