There shall be a department of law and a department of finance. Council may, in its discretion, establish additional city departments, offices or agencies to provide and administer city services, including but not lim-ited to public safety, planning and development, human services and public works, and may prescribe or reassign the functions of all departments, offices and agencies. Notwithstanding council's discretion to prescribe or reassign department functions as set forth in this section, no function assigned by this charter to a particular department, office or agency may be discontinued or assigned to any other unless this charter specifically permits its discontinuance or reassignment.