And how they maintain a fucking aircraft carrier? Only major powers can afford a one to begin with.
Yeah, exactly. To run an aircraft carrier requires an organised and powerful military force. It's not something a bunch of amateurs can do. If they have an aircraft carrier, they are most certainly part of the government of the Nexus, and it's a rather strong and well-funded government at that. It's simply not consistent with the idea of having a government with only nominal control, or of having a society where there is very little protection from the supernatural.
There's nothing wrong with having groups that go around trying to protect people, but they should generally be under-funded and over-worked, not supremely powerful.
It seems a bit ridiculous, honestly. I don't like the idea of the Enforcers being so overwhelmingly powerful, it makes it basically pointless to have good-guy characters in the Nexus, since any serious issues will already be dealt with anyway. From what you're coming up with, the Nexus sounds like it is actually safer than the standard Nasuverse is....
I'm also not remotely clear why there are Vampires and Werewolves still roaming the Nexus so freely when law enforcement groups have an aircraft carrier and all this other stuff. They should be able to bomb them to oblivion without much difficulty, and at very least drive them into hiding.
Collateral damage? I mean, it's not like the vampires and werewolves are all neatly filed into little Vampire/Werewolf Ghettos for any interested groups to level. They're everywhere, so bombing them into oblivion to a truly meaningful degree is likely out of the question. And that's ignoring the logistics of arming all the aircraft with anti-Vampire/Werewolf armaments. That said, werewolves and vampires are hardly the only hostile supernaturals, and the carrier is still a fuck-mothering carrier. Although with the Nexus constantly pulling in more supernaturals...
It's all a giant mess, really.
Well, sure, they couldn't kill them all, but a) the existence of an aircraft carrier implies they also have a lot of
other powerful weaponry (which would allow them to clear out vampire areas), because it is simply absurd to have the ability to build and maintain an aircraft carrier without the ability to produce other advanced weaponry and train a proper, well-funded police force and b) it means that vampires and werewolves have to go into hiding and avoid congregating en masse, especially in areas without civilians. As an example, look at what's happening to ISIS. The US air force can't actually wipe them out entirely, but what it
can do is stop them gathering in large numbers. Further, the US is hamstrung by not wanting to send in troops, whereas there is no reason for the Enforcers to have the same issue. Air support is
extremely useful to have, even when you're dealing with vampires and werewolves.