I think you could boil it down to a few things.
-
The jackals are known criminals, and this game takes place in London. Anyone who wishes to remain living in London (or the UK in general) without the chance of getting arrested would shy more towards the CDA on that basis. Proxy for example was directly mentioned in having a family that was caught in the middle of the dirtybomb detention. She has a direct reason to see to it that the CDA succeed in cleaning up the place. And you know, a nice paycheck doesn’t hurt either. Meanwhile, people who have no ties to the country and no reason to worry about the aftermath of their actions from the UK government are likely to be Jackals.
-
The CDA have been given full authority by the UK government to do their thing. Im guessing that the legality behind this would attract more of the former military characters, as its something their used to operating in.
My guesses for each character.
Proxy: CDA Has a family in the city and likely lived there herself. Needs money to aid in paying for relocating and starting over.
Fletcher: Jackals No ties to London at all, no reason to be CDA as far as I know.
Bushwacker: Could go either way. Im guessing CDA as their the defensive part of the equation here, and hes a defensive merc.
Turtle: Jackals along with Phoenix, will explain in a bit. Turkish, no known ties to London.
Fragger: CDA A former military dude who couldn’t readjust to a civilian lifestyle. Likely found the CDA to be familiar set up. I don’t really get “criminal” vibes from him.
Nader: Im guessing CDA, as it mentions she’s married and moved to London. She felt the call of the CDA and couldn’t resist.
Rhino: Literally said “f*ck this degree, I want to shoot people for cash.” That just screams Jackals to me.
Vassili: Not enough known.
Redeye: Desperate for a retirement fund after getting screwed out of his pension? I bet Jackals pay better.
Phantom: Obviously Jackals. I don’t imagine they have a much of a code of conduct like the CDA would, because they dont have to save face to the public. Also I’m pretty sure thats his hand holding the phone in the CW teaser.
Aura: CDA Tons of access to new shiny equipment that she already knows how to use (and maybe even developed herself).
Sawbonez: CDA Kicked outa the military for saving the life of a private…by stealing a kidney from an asshole CO. Can anyone say Chaotic Good?
Phoenix: Jackals Hes an asshole, infact a known asshole who was so arrogant that he even tested his nanobots on his own leg. Thankfully Turtle was there to make him a new one (This puts turtle into some kind of relation with Phoenix) . Spanish, no ties to London. The CDA likely wouldn’t want him after he lost his medical license.
Sparx: Jackals A conwoman. Already a criminal before we even begin. Shrug
Skyhammer: Im unsure really. It said he was court martial over an airstrike, but without many details. Going with the CDA.
Stoker: CDA Former fire support specialist in the UK military. Has a name tag, with his actual name printed right on it. Seems very official.
Kira: Jackals What the f*ck a PHD in a field I cant even pronounce is doing as a mercenary, I have no Idea. She has a rogue satellite under her control though, something I dont think the CDA would be comfortable with.
Arty: Jackals Total mystery. Wont talk to anyone. Is just here to make money and go home.
I think it roughly boils down to two from each class to each faction.