When having a mimic folder of a Blizzard folder with textures of the same name as the default Blizzard textures, these files are going to override Blizzard's default setup.
You either need to find the right textures you want to use and throw them into the RAIDFRAME folder with their correct names as the Blizzard textures OR you need to write some custom code and hook into the CompactRaidFrame/CompactUnitFrame functions and override the textures there.