Just dipping back to the discussion regarding A345/B772LR ZFW, etc, payload is surely going to be a relationship between DOW and ZFW, and then whether the payload available can be lifted of the available runway and remain under MTOW? Just considering ZFW alone is nugatory.
I see the DOW range on the A345 is 180-187T. The bottom end of that range is greater than the top end of the 300ER range. i,e, the A345 is heavier than the 773ER. At MZFW, the 345 can load about 142T fuel, to MTOW, though the 300ER is only about 112T fuel for MTOW at MZFW.
Clearly not the ideal comparison -no 200LR figures to hand. Anyone got them handy?