That's because the proportion is only a rule of thumb. Faces are bloody annoying; they're a mass of complicated proportions, none of which are strictly accurate. Sometimes the slight changes you make will work; sometimes it'll just make the face look weird.
Faces are very distinctive features, and it's very hard to get them right. Even if there is some slight confusion with the proportions, your faces look distinct from each other, which is definitely a plus. :)
Crescent Sky looks pretty neat. When using it, though, the center of gravity would be quite far in front of the handle, which is odd for a pistol. Still, hard to use weapons are not unheard of- it makes them harder to use against the wielder.
Sorry to spam your gallery a bit.