The detail with which the children are expected to complete their maps matches their ages. The oldest children must include the physical features, capitals and economic information of each country, while their younger siblings work on naming the countries. Each child works independently at his or her own level. Because they are all doing different work they can't copy each other. The different levels actually benefit the students instead of hindering them.
Students can glean information from each other and learn to work independently.
A traditional classroom situation is extremely homogenous. Being surrounded by 30 students one's own age only happens in school. College, work, and other real life situations are much more varied. The home school often reflects the age diversity children will encounter throughout their lives. The home school provides adequate or even better socialization and education than traditional schools, as well as having many other advantages.