I've seen multiple videos of people with multiple chameleons together that appear to be adult chameleons in the same cage. I was wondering if you could keep certain ones together in the same cage. Just outta curiousity.
Other than that, I would have to say you cannot keep more than one cham in one cage besides pygmies. One cham may be more dominant and eat all the food, leaving the other one stressed and starved. Fights could happen and both chameleons will get injured, etc. The videos you probably see are from "youtube" which is the worst place to get any type of chameleon information from.