Any vacancy that shall occur in any City office shall be filled by appointment by the Council; provided, that one person may hold more than one office and that, at the discretion of the Council, the functions of a City official may be validly performed and discharged by a deputy or another City official, or an otherwise qualified individual not holding office but employed at the pleasure of the Council. (Code 1982 § 3-1-5. Code 2012 § 31.05.)