My IP addressing is very structured. It's a 10.0.0.0 network where each site is a class B, and within each site my swtches and servers all have the same last two octet formatting.
Therefore to discover a subnet is extreemly wasteful if all I was is to find all my routers, or all my domain controllers.
i.e. DCs all end in 2.9. So I don't want to discover 10.0.0.0 255.0.0.0, which is what I have to do in your current configuration.
I want to discover 10.0.2.9 255.0.255.255. In this example I only want the second octet to change.
Discovery would be magnitudes faster and more accurate for what's desired by the engineer.