I think that they all just wouldn't like it but wouldn't blame Duncan for it. It's not his fault that he's made to marry one of the Targs (because I always imagine Duncan ending up marrying one of them as not really being his decision). Duncan is a lowborn hedge knight and I think it would further some of their already pre-existing beliefs of the Targs being tyrannical. Thinking this would happen where the trial doesn't happen. Maybe when Aerion called for the trial, he thought Duncan was a beta at least but then somehow it gets out that he's an omega and that makes Aerion think of a better way for him to pay for his crimes since omegas aren't capable of being knights (that omega wiped the floor with him). Idk who I would want Duncan to marry because Aerion could say that he wants to marry him or he could choose Daeron for Duncan to marry because he doesn't care for either of them. Idk just rolling ideas off the top. Even if it was a love match or something, I just think that Duncan has shown himself to be naive so his companions would see him as easily manipulated and still not blame him. It's like having several diehard brothers that hate your husband and love you down. Just remembered you said politically wise. Idk, I think they would want to go against this decision but what can they do, they can't rally enough support to start a full scale rebellion just yet (Helen of Troy Duncan maybe 🤔), I mean maybe they could. Imagine a rebellion starting because some Targaryen wanted a hedge knight bad. I'm burning the red keep down. Or it could go the complete opposite direction where this ensures their support of the Targs. Their loyalty for the correct treatment of Duncan. A kind of emotional blackmail.