The council, by ordinance, may create, change, and abolish offices, departments, boards, or agencies other than the offices, departments, boards, or agencies established by this article. The council, by ordinance, may assign additional functions or duties to offices, departments, boards, or agencies established by this chapter but may not discontinue or assign to any other office, department, board or agency any function or duty assigned by this chapter to a particular office, department, board or agency.