Both male leads are or were in special forces (one a SWAT captain and the other an Army captain), and they both are men of few words, letting their actions speak for them.
Both female leads have their own careers and ambitions.
Both dramas have height differences between the main couple, no love triangle and reunions after a period of time has passed. (One is high school sweethearts finding their way back to each other. While the other one is a reunion after a rescue.)
Both dramas are dramas are adapted from novels as well.
Most importantly, both dramas are sweet and slow love stories with devoted male leads.