Going back through my notes, I have discovered that I erroneously have Dalvan explaining in a conversation that he is no longer in the top 10 highest ranking nobles, but is actually 11th. In fact, he is, at that point in time, 10th. The birth of the person who bumps him down to 11th in fact happens later that year. I will need to go back and edit that conversation.
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See the updates thread.