Right, so first of all, I ask all parties that they won't make a big deal out of this. Whether Riverrun can or cannot be traded this turn will not result in anything major, so lets take things as they are and not blow it up, as we, as a community, always have the tendency to do just that
My decision is, that the rule is faulty and should be reworked. There is no reason why a settlement should not be traded if it is an impossibility to besiege it before the trade and the unit disbanding can happen. To this end, I agree with the interpretation, that something shouldn't be a warzone simply because it borders an enemy province for reasons already said above. This whole warzone word should be taken out anyhow. That said, a rule is a rule, and no one should be punished for anticipating something according to the rules. So here is what I would like to happen: the settlement trade will NOT happen this turn as to not make it unfair for Lannister. The rule will be reworked however, applied for next turn, and if stark / tully meet the conditions next turn, then they can trade the settlement next turn.
Regarding the settlement trade this turn, that is my decision. Regarding the rule rework, here is my !proposition!
- Two factions can trade maximally one settlement per turn. Such settlements can only be traded if they are not in danger of being besieged by any number of enemy units, AND the switch, along with the disbanding of units can happen before the settlement could be besieged. If such settlements borders an enemy province, the two players trading the settlement must notify their enemy(s) that the trade will happen. Their enemy(s) may show proof that the settlement can indeed be besieged to prevent the trade.
+ Some interpretations:
- I have no idea how to define which provinces separated by sea should count as adjacent, but the other parts of the rule apply
- As to not screw with the possible element of surprise, notifications should only be sent if provinces are adjacent, and you are at war with the faction (one party claims that there is a war)