Port forwarding for two Xbox consoles (for open NAT) Asus RT-N56U

In xbox live games we often see "moderate NAT" warnings, and most if not all of the time going back to the dashboard and hitting "test xbox live connection" will resolve the problem.

But I now want to set up port forwarding and a static IP address for both consoles. I need to open:

Port 88 (UDP)
Port 3074 (UDP and TCP)
Port 53 (UDP and TCP)
Port 80 (TCP)

I can forward these to one IP, but ONLY one. How do I go about forwarding the same ports for two consoles. Is that even the goal here? I just don't understand! I hardly understand what I am writing about, network configuration is my ultimate enemy when it comes to software troubleshooting haha

We are using the Asus RT-N56U router

Thank you for any advice.