One thing established early on is that vampires are solitary, but they maintain some social and political connections to one another. Without that there wouldn’t be much room for a group of PCs. But do your NPC Kindred follow suit?
Nothing now can ever come between us
As we hide and watch the city burn
There is much that I still want to tell you
But now is not the time to speak of love
CHVRCHES, Now Is Not The Time
A group of PCs should have a stronger reason to work together than “you’re the PCs” especially in a game where personal plots are a major feature. Three or four vampires have very good reasons to meet at the Succubus Club and not decide to go adventuring together.
So, what’s my motivation?
External threat, general or specific, is a classic. The Kindred PCs of Gary can only trust each other when visiting Chicago. Refugees from an invasion will have to work together to establish new havens, at least for a while. And there’s nothing like a common enemy to bring a community together.
A mutual interest (beyond seeing another night) might provide a stronger tie. Baby Chorus is just the first band in the Vampire settings, and that’s a loose and amicable social arrangement rather than something political and “important” like a plan to take over an unclaimed domain. Probably a healthier basis in the long term too...
It could be something mystical like an unseen connection, which is quite possible in Vampire but seems more suited to Mage or Werewolf, as the supernatural is usually just an added problem for the Kindred.
And then there are broods, linked by blood. Vampires can pick their family, but the choosing is generally one way, bringing in a mix of generational conflict, sibling rivalry, and of course the small factor that your sire probably killed you to make you like this.
The covenants in Requiem are a source of mega-coteries with different shared interests than Masquerade’s sects. A cross-clan religious group like the Lancea et Sanctum or the Circle of the Crone could add some interesting complications to a Masquerade city’s political scene.
It’s easy to create a city full of solitary vampires, so look at what might connect them and motivate them to work together, play together, fight together, kill together...