G. chiragra is one of the most aggressive of all stomatopods and one of the few where large adults rapidly escalate fights dispensing with the usual threats and probing. If the female is not sexually receptive, there is a very good chance that the larger animal will kill the smaller one.
G. c has a mating system called mate guarding. Typically the male and female share a cavity for a few days with the male guarding the female driving off intruding males. As soon as the female lays her eggs, he leaves the cavity and does not return. While I haven't studied it G. c, in other mate guarding gonodactylids, the male and female recognize one another for a couple of weeks and do not attack, a good thing since the female is rearing eggs that he fertilized. However, after the eggs hatch and the larvae leave, former pair members will fight.
Your problem is to determine if the female is ready to mate. If she is, you could probably establish the pair. However, you would still have to separate them once she reproduces. If she isn't, you will probably end up with one stomatopod.
G. smithii have a different mating system and females will mate even when they are not ready to lay eggs. On the other hand, they do not usually pair for any period of time and fights are likely to break out. Still, they are far less aggressive than G. c.
Roy