Megiddo, I think you point out something really good, but now I am going to twist it abit. If the Order were not allied with the Corsairs, it could probably be the perfect faction. The paradigm of the "Good Guy" Morally strong, powerful ideology, fighting for humanity, they dont bother humans, just nomads. It would be great, everyone wants to be the superhero.
But thats just the thing, the Order would have no flaws, it would be perfect. The faction would have no diplomatic or ethical drawbacks. No faction in the game is all "good" and to be honest they shouldnt be, it's not realistic. I kinda like the thought that the Order has to sell out a bit to the Corsairs. If the Order was not allied with the Corsairs, they would be completely surrounded by enemies. Nomads, Bounty Hunters, Liberty, and if the Order wasnt close with the Corsairs, the Corsairs would be hostile as well.
This is the reality of Sirius, nothing comes without drawbacks. So we dont say the Order wants to be allied with the Corsairs, but they feel without that Alliance, they would not be effective in their primary role of fighting nomads. So like every other faction, they have to compromise their own morals. It's very human in the end, and thats what it comes down to. In real life, many diplomatic alliances that occur, dont make a whole lot of sense, but they fill specific purposes, which people may agree or disagree with. Just because you dont think something makes sense, doesnt mean it isnt possible. Look around the world and you see people allied that make absolutely no sense, doesnt stop them from actually being allied.