i think if impossibile in one cage there are more factor that decline this idea ...
chamaleons of different species have different habitat , and also if this different for us will be nothing for chamaleons could be all.. and more there ll be stress for eat and for make basking ... there is a lot o thing ...
it's usually say that one cham one cage and it's correct for me...
it s possible take the same species and same sex togheter but there ll be a good space and habitat for all 2 3 chams...
but it s always better one cage one chams if you can !!!