The key word here is ‘reasonable’ and that varies from place to place. Insurers can only tell you what they think the potential risk of a certain building in a certain area is.
An apartment on the 10th floor of a high security building probably doesn’t need double deadbolt locks. But a unit in a building that’s easily accessible from the street in a high crime area needs all the help it can get.
It sounds like your unit is OK by the insurers’ standards and that will be enough for the landlord who may be reluctant to pay for additional locks without good reason.
But the other key issue is your peace of mind. Many police stations have crime prevention officers who conduct security audits on homes. Ask them what’s reasonable for this unit.
You can always change the locks at your own expense provided you give the landlord a key within seven days. You will probably need their permission before you start adding additional locks or security devices