I am not quoting theory, I am quoting field measurement. For a unidirectional flow from Olympic Park, both-side loading is achievable, as nobody is alighting. Likewise, from the very diagram which Tony cited, on 2 min track headways, a train can have a 3 min platform headway, and back to a quite achievable 60 000 per hour.
Can trains peel alternately left and right grade separated when approaching Flemington/Lidcombe, or is that a flat junction?
The French carriages, which have three doors per side, are also substantially longer. Recall, the original Sydney design made provision for a single-leaf door as well as a double-leaf one in all vestibules.
At all times, railway capacity in Sydney and Melbourne has been stifled by useless managements feeding gullible politicians, but transport hobbyists shouldn't fall for the spin and the lies.

Roderick./