I’ve almost never statted an NPC; it just isn’t necessary. Basically, since the number range is so tight, it’s easy to figure out how competent a guy should be. When in doubt, you can always eyeball the lifepaths for an appropriate number of skill points.
I will say, however, that main adversaries SHOULD be statted (like, the evil NPC overlord your characters are struggling against, etc). That’s always been useful for me, to understand these guys and gals better.