Import and replace similarly names shaders


Greetings! In my workflow I receive meshes with often more than 50 materials applied to it, all simple Phong shaders, with specific naming conventions. I have created a new collection of shaders, each being Arnold shaders designed to replace the Phongs and with identical names. I was hoping exporting the shaders and importing into the original scene file would simply replace the original shaders with the identical names, but this instead seems to apply the name of the imported shader file which I’ve saved as a .MB file to the beginning of all the shaders instead of replacing them.

I seem to remember being able to do this once but seems like it doesn’t work anymore. Am I missing something?