Male GTPs do fight, biting and constricting each other. Often these fights result in sever damage or death to one or both snakes. There is a report in Herp. Review of an adult male killing and eating another adult male.

I would not recommend tring to put more than a pair of animals together at a time. Feeding and record keeping for a pair together can be a nightmare. Sometimes there can be dangerous aggression even with a breeding pair. Robin