I ran into this exact problem a few weeks ago, here’s the solution:
- Import all the materials, let it create 25 brushed metal materials.
- Choose one of those brushed metal materials to be your “master”, I’d rename it something like “M_Metal_Master”.
- Select all the brushed metal materials and right click -> Asset Actions -> Replace References.
- In the Replace References window select the “_Master” material.
- In your case you probably don’t need to save the dirtied assets. Leaving this unchecked will remove the 24 other metal materials from your project.
- Hit the Consolidate Assets button.
Now you should see that all the references to your other 24 materials have been replaced by references to your _Master material.