When Queen Mother Joongjeon's true role in the overall plot was revealed last episode, I was hoping that we would see some guiding principles toward a long term goal. Instead, Queen Mother Joongjeon's schemes become increasingly bizarre. Even Dae-mok is standing off at the sidelines, a little bewildered but ultimately fairly indifferent as to her actions. There's no obvious way anything Queen Mother Joongjeon is doing could hurt Dae-mok, after all.
For that matter it's not really clear how Queen Mother Joongjeon's actions are much of an inhibition on Prince Seon's long term goals either. Queen Mother Joongjeon is just setting up complicated situations by which Prince Seon and the other Seon can tragically pine over Ga-eun. This is accomplished by putting one, two, or all three of them in mortal danger at random, cue the sad scene music.