Why does Rick or Shane's perspective matter to the group? On the one hand, both men are police officers, therefore predisposed to leadership (or crowd control), but on the other the symbolic system that allows them a place of power in the world ceased to exist? Thinking back to episode 2 of this season, Rick even makes the point to Andrea that he is not a police officer due to the end of the world.
Why does Rick still wear his uniform? I'd argue that is a kind of inverted interpellation. Or ideology from the back end of production. Althusser argues that we are always-already in ideology, and interpellation is that moment where we intentionally or unintentionally enter into the matrix of an ideology. The common example of interpellation is a scenario when some punk is walking down the street, and from behind he hears someone say, “hey you!” The punk turns around and realizes that the shout came from a cop. In this instant the punk finds herself as a subject integrated into an executive and legislative networks of power. Althusser is not saying that these networks of symbolism just poof into existence when some punk is 'called' by a cop. The argument goes that we are always-already integrated into several sets of meaning, and when we are called into one system of meaning more significantly than another we become what we are for others.