The assessment from your SM sounds reasonable.
The reasons for the discrepancies are probably because the EPA Regulations are the bare minimum for safety. Fire & Rescue NSW recommends owners and occupants consider higher levels of protection than that stated in the Regulations. Some owners and OCs opt for the higher level of protections as recommended by the NSW Fire & Rescue.
Extract from Real Property Services:
It is the Owner’s responsibility to install, replace and maintain any smoke alarms within their individual unit. This includes replacing the batteries and testing once a year.
The exception to this is if the smoke alarm was installed by the Owners Corporation. In that case, the owners corporation is responsible for maintaining and testing the smoke alarm.
If an individual lot owner fails to replace their smoke alarm once it has passed it’s used by date, it would not affect the Owners Corporation’s strata insurance and The Owners Corporation would still be compliant with the Environmental Planning and Assessment Regulations.