This series looks to me like a clever, funny weave of classical opera (mostly without singing, but there's are balcony scenes) and British mystery, and seen that way, it's brilliant! Like opera, the show is highly stylized, it's an episodic, romantic melodrama with upper and lower class characters, royalty, beautiful women in gorgeous clothing, and evil agents of Mussolini's government .These nearly entrap both Inspector Ricciardi and his closest friend. Overall, it's a morality tale (like most operas) while simultaneously a series of engaging whodunnits (think Poirot). There's even an opera singer who, in the end, sacrifices her future for the inspector's happiness!
I'd love to know if this structure was intentional or accidental.