My reasons for not using a gang right now:
- First of all, a gang job is noisy: even when they do a diversion to take the guards attention elsewhere, the obvious response for their action is an increment in alertness and security: I don't think we want it right now.
- Second: we can't control the possibility of casualties, and we are trying to avoid that.
- Third: We have nothing yet to bargain with any of them. After we enter in the place, we could at least defy them to do the same and show us that they are the kings of the street (ok, this would probably not work for a gang, but for some wannabes, and maybe they will do).
- Fourth: Loot. The loot is ours. Let the others enter in the story after it's already taken.
- Fifth: Our characters don't know each other, and don't know if one or another would not betray the others once inside. Imagine gang members. Once they have what they want, why would they help the 'runners? I'd leave them to be caught in their place.
Now I'm tired of numbers...
But my vote is for us breaking in, in a stealth or social (or both) way, without any ganger support right now. I'd use them later. We disrupt the production, they make it stay that way. Don't know yet how, but it's my vote.