I don't know, but before I really thought that scifi and historical can't go well because they kinda contradict each other. Scifi is like futuristic and new, while historical involves the history and old stuff. But I've seen some anime that use these genres at the same time, and it went well. Gintama, for example, is one of the scifi and historical anime I can't forget! At first I thought it would be boring, but it went well (thanks as well to its comedy! ahahhaha).

Also, The Empire of Corpses went well because I pretty much enjoyed how they integrated some historical figures (both fictional and nonfictional) into its scifi genre.