I would not mix Chocolate Gourami with Discus. I have (twice) had CG and both times lost them after a few months to skin problems. They spawned several times too, and I raised several fry. But they are notorious for coming down with skin diseases. They are very, very sensitive fish, and require very good water.
As of course do discus, but I would say discus are more tolerant of minor issues. With CG in the tank, there might be more issues with the discus than without the CG. Given the significant high cost of good discus, risking them is not worth it.
CG deserve their own space. If ever I acquire them again, it will be in a species tank.