Let me try to put it in simple terms:
When you model for the game, the only thing that will be exported from blender apart from the mesh are the material name and the UV mapping. What you have as texture layers inside the blender material doesnt matter, only the name of the material will be used. You still texture it because you want to set up the UVs and test how it looks with all its texture maps applied before it goes in game, obviously. Notice that one unit in Blender is the same as one unit in DR/TDM, and it means an inch, so scale it accordingly before exporting.
Once you have the ASE file, you edit it in a text editor and replace whatever was in the BITMAP path for the material name you are going to be using for that mesh (if its a LWO file, then the material name inside blender should already have been the material path).
For static meshes, you need 3 folders - materials, models and textures. You put your model inside its folder, and the texture maps inside their folder (you can come up with your own strucutre or use the suggested folder trees). Inside the materials folder, you need a .mtr file with all the characteristics the material will have. The best way to do it is to find an existing material, copy it, rename it and replace the all the paths in there with your own texture maps'. Or, you can simply use an existing material and skip this stage.
Download this model here and check it out, you will see how the files are structured and you can use it as a base for your own (just replace files and rename existing ones).
Edited by RPGista, 18 May 2018 - 03:09 PM.