I'm short on time and will go over your thread more thoroughly when I can (probably later this week) but for what its worth, I have been rearing G. portentosa with Elliptorhina javanica and an additional small colony with B. dubia and have been finding that the G. portentosa almost always dominate. It will take time, as the adult hissers are more 'dominant' than the nymphs and will outcompete other species and some of their own kin for space and resources. The prime "territories" (i.e. best hiding bark/branches, warmest locations) are always dominated by the Malagasy Hissers while the other species are forced to reside in less-ideal niches.

My setup is somewhat naturalistic, with bark, log material, and some plant matter in there. The Hissers take the best locations and force the other species to hide under smaller, broken and fragmented pieces of bark and debris in the enclosure in this setup. It has been about 4 months not, and the G. portentosa are reproducing and growing in numbers and my E. javanica in the same bin have been reduced to half their numbers (out-competed and cannibalism by G. portentosa).

With that being said - these colonies are not treat with perfect care. They are my lab pets and receive lunch scraps and occasional mistings...