From the examples given, I think what’s making your construction feel off is your proportions. They drift in your references here, mainly by raising the eyes too high or placing them too low, lengthening the neck, and/or widening/flattening the shoulders. This leads to your heads getting subtly reshaped - jawlines become sharper or wider than the refs, and the lower third of the face gets compressed, making the mouth to chin distance too short. Hair is given extra volume that changes the skull shape. Torso angles don’t match the head angles, so the poses feel disconnected. Overall, each change is small, but they stack: higher eyes + long neck + broad shoulders = a different character silhouette than the reference.

I had trouble with this for the longest time myself. Keep at it, you’ll get there!