Not sure if you can or with forwarder, but this is pretty simple in the resolver (unbound)
You can just do it in the custom options box..
server:
rrset-roundrobin: yes
local-zone: "google.com.local" transparent
local-data: "google.com.local A 8.8.8.8"
local-data: "google.com.local A 8.8.4.4"
So see how it changes the order of returned.
Curious what possible function this could? For pointing to googledns?
roundrobin.png
roundrobin.png_thumb