The biggest reason to delete any duplicate device that was found during Network Scan on many different IP addresses is that you are duplicating the work for the collector, network between the collector and device, and the device itself being polled for data.
Think of it in simple terms... It is like having a co-worker ask you what, where, etc.. for lunch while standing on your right side and then asking again from your left side.
Most Network Engineers will use the Loopback address of a Router, Switch, etc.. which is the most reliable interface because it is up as long as any other interface is up. This provides some redundancy when a device is reachable via multiple paths. If you have any other question, please feel free to reach out to me directly.