Adding to what Frate wrote...., It is true that everyone is not getting the same roster variations but besides that, what you need to understand is not what the rosters look like today for a new joiner but rather what they will look a year from now when somebody that is just starting the application process will actually be on the line.
As the 78 starts to get populated and takes on the passenger routes that are being done now on the 76, then the 76 at AJX will most likely be an all freighter operation with mostly China trips, the few Bangkok, Singapore cargo trips will be mostly for the first born preferred children, the redhead stepchild (A.K.A. New hire) will be doing nothing but freighter China trips with a mix of day trips and short rest overnight trips.
I don't mean to bring a sour note and like the rest of us I'm really just taking a guess as to how things will develop, but I believe this will be the most likely scenario.