That actually a rather interesting thing, seeing as I never took into account possible loopholes. You're allowed to make as many NPC's as you'd like, however, they must be inconsequential in their creation, meaning... they can have a slight backstory, traits and a personality, however, they're more plot fillers than anything. They're welcoming to be of a different origin or race, possibly even having some tie to your main PC, however, they need to be disposable and mean little to the IC in general.
I hope this helps.