Submeshes in a Meshed Model

I have been developing a model loader for a flexporter export. After implementing a Model - Mesh parent child heirarchy, I am now going back and revisiting my implementation of Materials/Textures.

Originally I implemented a one Texture/one Material for all Meshes contained with in the model. Now going back and reviewing, model data. I see that in reality, I will have a Model - Mesh - Submesh heirarchy.

Now for the question, what is the best way to represent this type of data within the model. Should I restructure all Submeshes with an identical material under on Material group and thus have Model - Material - Submesh, or can I still keep everything in a more organized structure of Model - Mesh - SubMesh - Material.

What is the best way to represent a model with multiple meshes and each mesh possessing multiple materials(textures)?

http://www.brent.globalcon.net/images/pilot_texture2.jpg