I think it would look better that way, yes. The way you're shading now, the sun is directly in front of the tree (behind the viewer), and slightly above. That doesn't happen very often, does it? Remember to think in 3D. Moreover, this flattens the tree, and even photographers avoid this light direction for that reason. The light coming a little from the side would make the trunk look more 3D. The sun is also usually brighter than that and casts sharper shadows, unless this is an overcast day.