Have Let Blender unwrap the UVs so that identical meshes can match

I have an idea. Have Blender let uv unwrapping to put identical mesh together match. It'll save time.
They should apply quickly like this, so you don't have to do it all yourself.

Why? I'm getting frustrated. When I unwrap it, the result is random and doesn't match the similar mesh of the UV mapping I'm tired of doing this. I have all ways to put it to fit the similar mesh of UV mapping. Why don't they let Blender do it? So What do you think?