[X][South] Marry Darvyd to both sisters.
The thing about having Vassals is that you most certainly don't intend to let them go and in fact, would then proceed to try and nom them, once you got your proverbial ducks lined up, in some fashion or another.
Having runaway Heroes running about, not being tied to the main polity in some fashion or other, is the exact opposite of having your ducks lined up. It is in fact, the worst thing that you can do. Because even if their goals are relatively innocuous and fine, it tends to be slightly troublesome in practice for us....like this current kerfuffle with between the Vynadian and Anti-Vynadian.
Also, this is exceedingly late and has absolutely zero chance of passing through but:
[X][SEC] Study Magic
[X][SEC] Trade Expedition = (Lowlands)
Should the vote to go get both Twins in, it would mean that we have a) one Hero that excels in the study of the divine, as well as the capability to not ruffle any feathers in the attempt, and b) another Hero that excels in smooth-talking (and wallet-loosening) everyone potentially hostile that we can meet....or gank them away if negotiations fail.
Thusly, we should strive for Study Magic action not the least because we have a Faction Quest relating to it but because we haven't even done it once. Think of the Mystic Hero as a Tech Hero, in this regard. And at least one Explore or Trade action should be done, if only so we can get a better bearing of the surroundings. Like say, the big mountain observable from literally the other side of the known world that has always been there since the start of the Quest.
You know, that thing. We should probably check on that thing.