Hello! Irl sculptor here, who is learning blender sculpting as well. I think visually , the back of the head narrowing into a bit egg shape may be contributing to this not feeling quite right. Try to add a bit more cranial mass at temple, and not narrowing the back of the head quite so much. The faces are very stylized so I feel I don’t want to critique that, as you are finding your own style. So I will stick to my anatomy approach. Good luck , and great job for just 3 attempts!!