In order to maximise the potential appeal of hostility (and increase my workload :D) a few ideas of a third team have been thrown around. This would probably be some kind of small resistance group who would utilise a mixture of fictional and re-world weapons (M4's, etc) and involve a very different approach to the other two teams. It would add an element of Counter-Strike type realism to appeal to gamers with a taste for the realistic rather than the fantastic.
If this is used maps will still generally be 2-team only, with predominantly NMO Vs GEC maps. A few will be of the larger factions against the resistance and possible one or two with all three.
Anyway, this is currently only one of a number of ideas under consideration as work is continuing on the GEC and will for some time.
As ever any feedback is more than welcome.