I like to do some research on the species I am keeping, and I like to provide them the optimum conditions they would have in the wild. This would include water conditions, diet and tank mates. I am not saying these fish won't spawn in less then perfect conditions. However if you do provide the ideal situation, your fish will spawn more often, your fry count will be larger and your fish are going to live to longer.
Unfortunately you haven't given me the size of your tank, which can be a critical key in your success. The two cichlids you have chosen should be okay together, but how you arrange your tank will help keep it more peaceful. Ideally you don't want these to fish to be fighting over the same part of the tank. While Caudo's are cave spawners, they like to be down on the sand, they love to dig in it, yet they want to be close to a cave or crevice in the rocks. The Xeno's like an open area of sand. I would put a pile of rocks on one end of your tank, to encourage the caudo's to stay on one side of the tank, while leaving an open area on the opposite side for your Xeno's. I think you need a minimum of 40 - 55 gal.
I have not had any experience with these cichlids forming harems, I have only had them pair off one on one. For the caudo's you will need to provide plenty of nooks and crannies so they are not all fighting over one cave.