Look at the Coen brothers. All their minor characters are as interesting as their protagonists. If the smaller characters are well-written, the whole world of the film becomes enriched. It's not the size of the thing, but the detail.
“The Leader will be a person with the management skills to coordinate the activities of the Team, and to assure that the Team remains faithful to the objectives of the incoming President.”
“It is only in adventure that some people succeed in knowing themselves - in finding themselves.”