Fuzuma
Unfortunately seniority doesn't come into preference bids it's only down to bid group therefore, all are equal in the bid group. Request are different they take seniority into account but even if you get a trip before the optimzer runs through the preferences it doesn't guarantee you'll keep that trip.
I had the same problem this month where my highest preference ended up given to 2/3rds of people not in the top two bid groups. Unfortunately as V1cutz said they don't care and there's not a great deal you can do.... Just roll with the punches....
