Hey William. I cant say much about the layout since I dont know what else you want to include in the scene. However, I think you should not make the ruin so straight and angular. Make it more crooked so it really feels like a ruin. Now it looks like a brand new wall in the process of being built.
Also I think it could look really nice if you model the bricks. You can first model the general shape of the structure and then use displacement to make the surface uneven. It can still be low poly, just so it is not completely flat and even. Then make a few types of bricks – with unevenly beveled edges and parts of them chipped off and place them around so that they intersect the original structure. That way you have bricks poking out and the original structure is the mortar in between them.
Also it might look strange if you have a low poly ruin and a tree that has subdiv modifier. I would make the tree without it.
