Ecotransit has produced a new video critiquing the current NWRL proposal and have an alternative vision for the NWRL. See that here: Ecotransit and the NWRL
WSPTU has written to the Minister for Transport pointing out the problems of building the new NWRL with tunnels which are incompatible with the existing Cityrail rolling stock - even if they are planning to have single deck trains operated by a private operator.
The history of the Sydney network tells us that rail infrastructure timeframes are very long and that things change over these long timeframes. We know that parts of the network have been privitised and re-nationalised at different times and for different reasons. We also know that people may want to develop or change the network in the future and this may require that the NWRL is compatible with other parts of the network. Making the new parts of the network incompatible with the rest of it seems to be building a potential inefficiency or redundancy into the system in a reckless way.