Limiting the factions involved was requested by the official factions who created the story behind the event in the interest of at least a degree of fairness. The anti GRN side is much larger, nobody can dispute that, the best that we can do is try to fragment involvement. If you want a Council + Colonials vs GRN open event in the Tau systems or something to the tune, please request.
I also updated the OP with more specific instructions about who is allowed to participate.