The County Executive shall appoint a single officer to head each agency of the executive branch, subject to confirmation by the Council as required by Section 322 of this Charter. The County Executive shall appoint the members of all boards and commissions, subject to confirmation by the Council as required by Section 322 of this Charter, unless otherwise prescribed by State law or this Charter. All employees of the executive branch, except those otherwise provided for in this Charter, shall be appointed and removed by the heads of the several agencies of the County government in accordance with the provisions of the County personnel law.