Explain the difference between Maurice and roger during their interaction with Henry, Percival, and johnny?

Maurice is content to topple the sand castles of the Littluns and continue on his way. Roger is a sociopath. He lingers behind throwing rocks and nuts at the Littluns. He aims to miss but that thin line of adults and rules from the old worls is evaporating. Roger finds pleasure in inflicting pain on others while Maurice simply doesn't care about the Littluns.