Umm if a clan to you never had hierarchy then all your clans probably sucked and you don't know what a real clan is .
In computer and video gaming, a clan or guild is an organised group of players that regularly play together in particular (or various) multiplayer games. Some people might say that a "clan" or "guild" becomes like a family, and that all opinions and decisions represent each single member in the "clan" or "guild". These games range from groups of a few friends to 4000-person organizations, with a broad range of structures, goals and members. The lifespan of a clan also varies considerably, from a few weeks or months to over a decade. Numerous clans exist for nearly every online game available today, notably in first-person shooters, massively multiplayer games, role-playing video games, and strategy games. There are also meta-groups that span a wide variety of game.
A crew is a body or a class of people who work at a common activity, generally in a structured or hierarchical organization. A location in which a crew works is called a crewyard or a workyard. The word has nautical resonances: the tasks involved in operating a ship, particularly a sailing ship, providing numerous specialities within a ship's crew, often organised with a chain of command. Traditional nautical usage strongly distinguishes officers from crew, though the two groups combined form the ship's company. Members of a crew are often referred to by the title "Crewman".
"Crew" is used colloquially to refer to a small, tight-knit group of friends or associates engaged in criminal activity. Also used in reference to the traditional "unit" of criminals under the supervision of a caporegime in the American Mafia. However, the term is not specific to (Mafia-affiliated) organized crime.
Crew can refer simply to a group of friends, unrelated to crime or violence.