I think if all adult members of the DRF would be killed, a member of the government would take over, perhaps with someone of the Court, like a council? Ove Ullerup and some other people?
I don't think that Marie would be able to take over for Christian, the order would be Joachim and then Benedikte. Henrik Senior would also not be able to be regent.
Soccer is a game for 22 people that run around, play the ball, and one referee who makes a slew of mistakes, and in the end Germany always wins.