More thinking and maybe I understand...
Are you saying I could take the Receiver and wire up all of the speakers to the out puts on the Receiver except for the Front Left and Right. For those channels I would connect from the Preamp Out Front Left and Front Right on the back of the receiver to a completely separate two channel amp. That amp would then power just those two speakers. So the end result would be that I would not be using the Front Left and Right channel amps on the receiver. In that case would I even need an integrated amp for those two speakers? Seems like I could just use a stereo power amp and control the volume from the Receiver. What might be necessary is for the receiver to have some sort of speaker configuration profile so that I could turn off all of the speakers except for the Front Left and Right Pre-Out as well as the SubWoofers. The subs would be used for both speaker configurations. I think the Anthem has something like that.