IMHO these are not issues concerning unbound but rather understanding of DNS in general. So maybe this is not the right forum.
To answer your question, what you are suggesting is not normally done. But it doesn't necessarily generate errors. You need to know what you are doing / what goal you want to achieve. If you are declaring two identical A records pointing to different IP addresses, then the resolved IP will randomly be chosen between all entries. It can be used as a load-balancer for the poor. Usually you have one IP (and one name) per interface. It doesn't matter what "device" that interface belongs to. Very often people use "service names" to point to some IP and then the name of the actual host the IP is assigned to is used in the reverse lookup. I.e. accounting CNAME acc01prd acc01prd IP 1.2.3.4 1.2.3.4 PTR acc01prd So you don't use the cryptic hostname to access the service, but if you do a reverse lookup you find out where the IP is hosted. But it all depends on what you want to accomplish.
