That is how I currently have it set up. It still doesn't solve the two cable issue though. Thanks @Sunshine

Thanks, Yes, I want there to be a switch between them. If that is the case, is there a way to configure the N600 as the primary router and have it fail over to the MR600 if DSL goes down?

I purchased the Archer MR600 to have a backup LTE connection to my existing DLS connection. The DSL router model is TP-LINK N600 TD-W9980. I got it all working when plugging the switch in to a LAN...