OK, here is another question, this time for Mikhail, so said in comment #9438
“You alos need to know if you assign a material from one object to another all this object (mesh) must have the same structure: if one of them has armature, shape keys or two or more UV-map it’s will be need to add the same thing to the second, so it will not broke out your armature, shapekeys or structure of the material.”
What would happen if I mix shaders in one of the materials and not in the other one, or I modify the scale of an UV map using a Mapping node in one of the materials and not in the other one, or even simpler, what if I add a color modification node in the middle of the graph for one of the materials and not for the other one? Will the assign material work if the material graphs do not have the exact same structure?
Thank you!