Network Scan - Finds a machine multiple times - DNS issue

When looking at the Network scan to find our non Windows machines it has found some machines multiple times.
The reason is that the server has two dns entries for the same IP address covering a current and a legacy domain name we use.
as example

ServerY has address of 192.168.1.10

it has a dns or hosts entry of 192.168.1.10 ServerY.domain1.co.uk ServerY.old-domain2.co.uk

So in the workstation list I end up with
ServerY.domain1.co.uk
ServerY.old-domain2.co.uk

It failed to login to the server as it isn't a windows or Linux environment so appears to not collect any information about it, and snmp isn't enabled on the device.

Apart from changing the DNS, which isn't a possibility at present due to legacy applications requiring the old domain ( its a long , long story! ) is there anything that can be done to stop the duplication of these machines with each network scan? A check on MAC address possibly , if one thing comes back with the same MAC it must be the same device surely, not matter what DNS returns for it.

Or an option to link two or more assets and state they are the same thing and to only report and count as one thing in future possibly.

Kind Regards,
Andy