(I'm planning to set up a VIP group. How are VIP groups usually restricted—full subscriptions or something? Yi Zui still doesn't quite understand, haha.)
Although Orb sending out three fleets was not all that different from deploying all its forces, at the outset they would still be facing an Earth Force that had not yet fallen apart. In essence, Orb, which upheld neutrality, had already violated its principles. Fortunately, it still had the fig leaf of dealing with LOGOS. As long as its deployed forces focused their attacks solely on confirmed LOGOS forces, it would be a decent cover story and a justifiable excuse.
But after a period of respite, once everyone who should leave the Earth Force had done so, the remaining Earth Force could naturally be deemed entirely under LOGOS's control. If Orb then deployed its full military, it would be even more justifiable. It might seem unnecessary, but reputation, principles, politics—there still needed to be a presentable fig leaf.
Durandal understood Xiao Ran's concerns and his intentions. Through this decision, Xiao Ran was also telling the world that the Earth Force was not Orb's enemy, and that Orb had never intended to violate its neutral principles by joining ZAFT in fighting the Earth Force. Orb was sending troops only to deal with LOGOS, the organization disrupting the world, and had no choice but to act for world peace. Once the Earth Force truly descended into chaos and fractured, when ZAFT, Orb, and even former Earth Force troops who had left to join Orb or ZAFT all identified the remaining Earth Force as forces controlled by LOGOS, then Orb's full deployment would carry the implication that ZAFT, the Earth Force, and Orb were united in dealing with the villains.
In any case, only a very small number of