It must be terribly unbalanced to have the wings so low. Why do so many artists draw the wings there? You need only look at birds and many airplanes to see that the wings should be at shoulder level, otherwise you'll tip over when you fly.
I mean, as long as we're nitpicking, may as well point out that a person would need a wingspan of at least several meters to lift their own weight. If the wings obviously aren't providing any physical lift it doesn't really matter where on the body you're gonna put them I would think.
You need only look at birds and many airplanes to see that the wings should be at shoulder level, otherwise you'll tip over when you fly.
(Presupposing functional wings that can support the creature and that the point of this exercise is aiming at balanced, horizontal flight) the important point is not being located at the shoulders, it's having the lift force averaging at the center of mass, the balance point. The avian form works because that is where their shoulders are, and mammalian bats/flying foxes can get away with it since they are generating lift all the way to their feet; but the center of mass in humanoids tends to be close to the hips, maybe slightly above the navel.
Another consideration is that birds can generally tuck their legs underneath themselves in an aerodynamic fashion, but to gain the same kind of aerodynamism a humanoid would have to bring them up horizontal behind the hips instead of under. Humanoid legs are effing heavy (easily 30% total body weight), and having them stuck out horizontal will net you a large moment arm which will only accentuate the rear-ward balance.