Was age 18 too young to become a parish clerk?

Edward Illegit son of Edward Corkil/Margaret Cowley bapt 16 Nov 1758.
John Christian became a parish clerk in 1688 at the age of 26, but most seemed to be older.

There was also Edward s/o Edward Corkill/Ann bapt 10 Mar 1730/31.

Because of the voting recorded for a new parish clerk the 1820 date of death for Edward would be accurate.

Sue