Hierarchy plays a key roll in The Wire. Much like when the queen-demoted-to-pawn described the game of chess, everyone has a place and a roll.
These predetermined jobs both lend to the structure and flow of "the game" and constrict information. The Police protect and answer to the public. Part of the protection is spin control. Each person reports to the next person in line. They are more worried about job security than truth. No one wants to "give a fuck" because in the game, giving a fuck/trying is the only way to lose. The drug war is ongoing. It is not going to be fixed by any one man. Taking away a dealer just promotes the next guy.
The dealers working in the corridor do not understand the chess game because no one becomes the king. Checkers is about attacking, and bettering your pieces by becoming a king. Chess is about strategy and protecting one entity. The pieces have no hope of promotion to the ultimate level, but give their lives anyway in hopes of doing their part.
In the projects, promotion is unlikely, but they can play by their own rules. When one is broken, the punishment is harsh. In the cop world, when rules are broken, they are brushed aside and covered. This is all in hopes of promotion. Lack of communication and turning a blind eye smooths out a difficult job. It is when information is given that people work and see harsh reality.