One other minor detail - if you have more seats (which does ususally mean a heavier aircraft), you can divide the operating costs over that higher number of seats.
Uh huh, fine theory... but what if the majority of 767/A330 operators don't want that extra seat capacity?
More seats = Heavier Aircraft = More seats to be filled before break even.
Bang goes the A350's advantage.
The A350 was directed at EK. Airbus are so blinded by the prestige of have EK on their order books they've gone for a "more seats and more range" approach and have completely missed the whole point to the 787:
An A300/767/A330 replacement in one platform.
As for breakdowns... its simple
787 = Composite
A350 = Metal
Nuff said on that.