Kiara, I'm thinking text based. I'm terrible with maps and to be honest, rather than seeing the city as a whole, I imagine the city and the locations in directions from other locations. It's not fully mapped out in my noggin', just basic areas.
PC owned/run groups can acquire and even create their own places (shops, services, etc) and upon creation, that group will own them. Each place can be taken over, depending on how loyal the owners are (if they are too loyal to turn, they can always be killed and replaced by someone a little more loyal to YOUR cause).
Let's use
Cutters and Carvers for example. The twin brothers, Kander and Keith, are members, allies, or loyal workers for the Night Eyes (I haven't decided their relations yet). This makes them difficult to steal, business wise. If the Crimson Edge wanted to take over Cutters and Carvers, you would either have to convince the brothers to pay assist you over the Night Eyes(A), force them into your pocket(B), or kill them and assign someone loyal to you to take their place(C). Each of these options create a very different scenario. Let's move onto more examples.
A.)
You Convince the Carver Brothers to be allies and to ditch the Night EyesThis is a good option because they are joining via free will. They won't feel forced, oppressed, or enslaved, making them more likely to be more loyal than if they were forced.
B.)
You Force the Carvers into an Alliance via threatening each other's brother/family/business. This is a dangerous but powerful option based on fear. Depending on the NPCs, fear can be a better motivator, or your plan's downfall. If you force an NPC into alliance via fear, they may seek out assistance from another group, or have very little loyalty if they believe they can get suitable protection from another source.
C.)
Both A and B fails. You kill the Carvers and Put Bob Barton as Woodcutters Owner (just an example, don't forget)You have taken out the risk of the Brothers betraying you because they are dead, however the business changes. Your new owner may not have the required skills to keep a legitimate business running, or the skills to even make a corrupt business last long. The Owner can be an NPC or PC, but you run the risk of having to dance around loyalty all over again with a New Owner.
I hope this helps. Also, just because you take over a business, doesn't mean it is always yours. I would require various threads of people 'watching' businesses, defending from extortionists, or saving businesses from destruction via physical or financial. The more places you control, the more difficult it is to control them all effectively because that requires SO many more threads.
Robern, the Sun's Birth, and the Night Eyes are the Crime Syndicates. Dastana is a small time gangster with no ambition for control. She's just not someone to screw with. Just another strong NPC that could be influenced, or influential, in Sunberthan Society.
I don't consider Dastana as a faction, though she can be joined, you just won't get far in her current state.