3 different skill sets, talents, and positions. Art directors, graphic designers, production artists make up the front end department team. Traditionally (before the great recession,) designers would turnover about every two years, art directors would stay or go with accounts unless they are a partner which they often are, or startup their own place. Production artists could make a career of a shop, often the most loyal with deep-rooted skills.
Pressmen made up the back end; master, journeyman, apprentice. The masters usually have the longevity and hard-earned skill of course. Pressmen at sign shops? Who would have thunk?