Yes they are. All cluster b personalities are at their core- narcissism on a spectrum that manifests in what way their brain is designed to.
Isn't everything on a spectrum these days? They want to put OCD in a category all it's own now. No more cluster c for those guys. But there will still be this massive spectrum. Who gives a fuck anymore? At its core, narcissism in the lack of interest in having genuine relationships with anyone other than yourself. You could fit too many people on that spectrum these days.