NSX-v Router OSPF

Hello Gurus,

I have a question regarding  the OSPF, why do we use protocol address within the the same subnet of the Forwarding address

Fwd address makes sense as it's DataPath module, and we configure router ID to be the transit interface towards the Edge router ... it's ok, But why do we should assign the protocol Address within the same subnet as the forwarding address it should form adjacencies using it's router-id ?

Is this correct?

Thanks in Advance for clarifications

CHEERS