The key to porting units successfully is to combine all the separate meshes into a single mesh with a single material and texture. A mesh can contain disjoint parts that so there is no problem with horse riders, etc.
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In this example I have to combine 4 256x256 textures into a single 512x512 one and then rescale and position the UV mappings. In the UV view S (for Scale) followed .5 will half the scale, S, X, .5 will half the scale in the X axis if you only need to combine two square textures into a single rectangular one.
My combined texture with fixed UV mapping in Blender ...