Here is stylished old tree I modeled in Blender.

• Small branches are all joined together, but 3x biggest branches on top of are separated from others, so it's easy to move/rotate/copy them as u like; if you see the reason for that.
• All leaves are joined together, but are systematically in a different layers.
• All individual objects contains 4k texture maps, and there is in total of 5x individual materials.
• UV maps are made automatically. There is No overlapping UV's.
• Other file formats are all exported in Blender, and I can't test how they work in their own softwares, so I hope they work just well.

I hope you like the tree.And have a Nice Day!