I’ve never used internal XOs (I built my speakers without XOs), but my understanding is that they are in the speaker, so if you connect to the speaker terminals you will be using them.
So you could just connect the Parasound to the LF terminals on the speakers and the Rouge to the HF terminals, adjust the Parasound to match volume, and you’re done.
But I've never done this so if I were you I'd wait for someone else to confirm