In all townships in counties of 3,000,000 or more, in which township assessors are elected, the township assessors shall be ex-officio deputy assessors to make the assessments in the townships wherein they are elected but those ex-officio deputy assessors shall be under the direction and control of the county assessor in the same manner as other deputy assessors, subject to the rules and regulations prescribed by the county assessor and the board of appeals. The compensation and expenses of the township assessors shall be determined and paid as provided in Sections 2-70, 2-75, 2-80, 4-10, 4-15 and 4-20. If in any township the ex-officio deputy assessor is not able, within the time allowed by law or set by rules and regulations prescribed by the county assessor and the board of appeals, to make the assessment in the township, any additional deputy assessor or deputy assessors required to make the assessment shall be residents and legal voters of the township and may be appointed by the county assessor. For failure to complete the assessment and return the assessment books within the time prescribed by law or set by the rules and regulations of the county assessor and board of appeals, any township assessor may be removed from office by the order of the county assessor. All clerks and deputies shall take and subscribe an oath of office to honestly and faithfully perform all the duties of their respective offices under the direction of the county assessor. The county assessor, the clerks and deputy assessors, may administer oaths authorized by law to be administered by assessors. The number and compensation of the clerks and the deputies (other than the ex-officio deputies) shall be determined annually by the county board and shall be paid from the county treasury.