>>96785435
Choosing Faces (Social Engineering p. 20; pic related) claims that an ordinary person often doesn't have any Influence skills (Diplomacy, Fast-Talk, Intimidation, Savoir-Faire, Sex Appeal, or Streetwise). But Template Toolkit 1 p. 17 clarifies that every person should have at least one Influence skill.
Therefore: IMO, Choosing Faces is too restrictive, and a normal middle-class person knows both Diplomacy and Savoir-Faire ([Culture] Middle Class), since "[Culture] Middle Class" is "a subculture that has an established code of conduct" (Basic Set p. 218).