I suggest that fief owners can set an amount/percent of S&D to be available ONLY to non-clan members (external). The rest is available ONLY to clan-members (internal).
The internal amount should be somehow limited, so a clan doesn't stop trading for non-clan members totally and every clan is forced to let other clans into their own territory. I don't want to ask each clan I pass by how much and where I want to trade, this is kinda stupid.
It would make life for both, traders and fief owners much easier, because they can "secure" some of the S&D for their own needs. But it would force every clan to make trades with other clans.
(Created new topic because of wrong forum)