Nayther bag nor bug

• The Grand Old Duke of York: (nursery rhyme) "The grand old Duke of York,/ He had ten-thousand men./ He marched them up to the top of the hill,/ And he marched them down again./ And when they were up, they were up;/ And when they were down, they were down;/ But when they were only halfway up,/ They were neither up nor down" → according to some accounts, the rhyme refers to Prince Frederick, Duke of York and Albany, whose military service took place during the Napoleonic Wars
  • Wikipedia

• neither big nor small → if Shaun is Big Napoleon and Shem is Little Napoleon, then Shem-Shaun is the "Petty Napoleon who is neither big nor small"

• big

• beag: (Irish) small

• bug: an insect → scotcher grey