yeah i could really only seeing it work if the ejbd was way bigger than the female and IF she accepted him as mate, though if she dont accept him then he still more than likely will get stressed out to death, but its really hard to find a grown ebjd and a baby would def die from the female picking on him
if you get rid of rd and con you still cant get anything but maybe some dithers or some bottom dwelling non-cichlid as two grown demspeys especially a breeding pair are already pushing it for a 50g