Complex sentence: The land provinces within the Great Powers which contain supply centres are generally named after a major city in the province (e.g. London, Moscow) while the other land provinces within the Great Powers are generally named after a region (e.g. Bohemia, Apulia).
Split into simpler sentences: The land provinces within the Great Powers which contain supply centres are named after a major city in the province (e.g. London, Moscow). The other land provinces within the Great Powers are named after a region (e.g. Bohemia, Apulia).