Cordylus tropidosternum - couple or trio

[Oviraptor]

Hi, I have a couple of C. tropidosternum and I´m building a new terrarium 120x50x50 for them. I would like to add one more adult female to my couple, but I´m afraid of fights between females. I can´t find any informations how they lives - in couple or in group. Have you any opinions with this?