User blog comment:B214/Question and Answers 2/@comment-117.196.181.215-20140224174554/@comment-24501441-20140225020010

I agree, there are definitely politics involved in marriages with the heirs to the clan, and as I stated, I'm sure the individual clans wouldn't come to terms with such marriages (usually), but I do think it's possible. There doesn't need to be another sibling to become the next heir (Millicas is heir of Gremory after Rias, did Ajuka have another brother after Diodora's death?). But to reiterate, even though I think it's possible, I highly doubt an issue like that ever happening due to the politics involved and the natural greediness of devils in general. I don't see any families willing to lose an heir of their clan.