Your points are well made. I guess there is no perfect answer. Certainly the single Rogozhskoye Cemetery under Category:Religion in Moscow looked odd. Religious cemeteries might be better categorized under the religion - e.g., see Category:Jewish cemeteries and Category:Roman Catholic cemeteries if you wanted to use or create appropriate categories for specific religious connections. In many/most countries, cemeteries have religious connections as a rule, but Russia/Moscow is obviously different here. I hope this helps. —