You can use only bomb model.Bomb Model;Polygon : 1536 Vertices : 770 At the same time you can use all model.All model is high poly model so you can use decimate the models polygon.
OBJ (OBJ, filesize: 12.7 MB), FBX (Autodesk FBX, filesize: 4.33 MB), BLEND (Blender, filesize: 3.79 MB)