Inconsistencies with the astrologian questline and the Durendaire family

[RobinMalvin]

House Durendaire is the one in charge of The Observatorium, so it is no wonder that their children will be inducted in the art of (Ishgardian) astrology since birth. I think by what Jann said that he's been studying astrology for "more than thirty summers" means that he's been studying astrology (not Sharlayan astrology exclusively) for as long as he remembers.

As for the succession line, I'm more inclined to believe that Jann is actually the third son of the family and originally third in line of succession. When the oldest son (Carvellain) dissappeared, he became second in line. When he started to promote Sharlayan astrology in earnest, I assume House Durendaire was none too happy for it (his uncle was certainly pissed enough) that they rearranged the succession order so Jann now is considerd third in line of succession, at least maybe by House Durendaire. We haven't seen a lot of members of the Four High Houses so I'm not at all surprised if the second son of House Durendaire will remain unseen.