YOu do not need a texture importer to add multiple textures to a mod. Ask ancientwanker, because he somehow made mulitple heraldric textures within his hugemod. it may have been n00b +some random numbers there. I think extra horses got in too. Regardless, I really like the idea. You could change the dark nights and khergits to be one faction, and make it the conditerri (spelling on that? that is the italian version, do not know the french or english). Essentially, they were soldiers who had deserted or been released from service, so they roamed the country in bands, occasionally even holding cities at ransom.
Also, i second the conversion to WinZIP, if possible