Like they don't know each other and might have slight curiousity towards each other but they don't know each other and perhaps the plot doesn't make them intersect until halfway through, and maybe then they use their to-be-married status to work together and overcome some political plots or similar.
Ive seen too many dramas where they're arranged to be married and due to pride or whatever they almost blindly shoot themselves in the foot(because ofc they'll eventually fall in love blaha blaha) . I'd rather see a drama where they're at least curious about each other before they vehemently decide to be against it.