It seems to me, with no Airbus experience whatsoever, that the Airbus family have more commonality than most Boeings. The 777 and 787 are really quite different machines, including some differences that are vastly different (air systems being an obvious one) but they are flown on one type rating. Why is it possible to fly the 777/787 but not the 330/350, when Airbus, as I understand it, has gone to a lot of effort to ensure commonality of logic etc in their machines?