Both of these dramas are historical dramas that involve succession to the throne. Haechi and The Red Sleeve are based on family members. Both dramas have strong and smart female leads. The male leads are dunning as well.
Both are set in a fantasy world where the zombie apocalypse is eminent. Both dramas starts by showing how the outbreak supposedly started and how the people around them adapt to the situation. The origin of the pathogen is different but it still has the same effect. Not your typical zombie shows.