Year of the Astounded Beetle

In this year, Brutha was perhaps two or three years old. He remembers that in this year, he first saw an Ephebean coin, a derachmi. As Brutha is described as "a youth" during the events of Small Gods, which we are told took place in the Year of the Notional Serpent, and both years fell in the Century of the Fruitbat, it is possible the two years are separated in the calendar by as little as thirteen or fourteen years and no more than about twenty years? A minor point for those dealing with the Discworld Timeline...