Assuming you are in NSW, here is some info about where to locate smoke detectors: https://www.fire.nsw.gov.au/page.php?id=443
As per the link, it might well be the case that only one is needed for each storey. And the recommendation says “it is better not to install them in kitchens, bathrooms, laundries and garages”.
I have a two floor apartment in a fairly new complex and we only have one per floor. The detectors inside each apartment are mains powered (with battery back-up) and are not connected to the building's Fire Panel (meaning that the alarm is local – but it is loud enough inside the apartment). We also have detectors in the Common Areas of our building that are also mains powered but have a central battery back-up. These are connected to our building's Fire Panel which will ring bells/alarms everywhere if one goes off.
We also have water sprinklers in each apartment and in common areas. Only if one of these triggers will a call will be automatically made to our monitoring service who in turn will call the fire brigade.
Are your internal apartment detectors connected to your building's central Fire Panel? If so then it would be an OC matter to maintain them. Ours are not, probably because of the number of false alarms that would happen.
Perhaps it not a law that your manager refers to but a recommendation? But if you really wanted to install more detectors, you could of course buy stand-alone ones even from your supermarket. These are battery powered only, so you need to check/change the battery often.