The first method seems viable if you have enough connection though.
To quote, my plan is having Charles managed to buy massive amount of stock in a short timespan. And subtly implied that he can just destroy the integrity of Dunois nobility status if he really wished.
Charles' nonviolent takeover on his family's Corporation and the threat following get WTF reaction from the rest of Dunois, even Charlotte looked at it as excessive. But considering how much they screw with his life, and that Charlotte has it worse, everybody knew and understand. Knight Templar Twin Brother indeed
On a different notion, Papa-Dunois is portrayed more humanly and less of an ass too.