If you already positioned the attachments in your skin and then afterwards duplicate your skin, the positions of each attachment should be intact.
You can drag an attachment from the Images node on top of another attachment that is already in a slot, to place it in the same position.
It's best to get the positions set up correctly in a single skin before adding multiple skins. Once this skin has been set up you can duplicate it and then use Find And Replace to set up the duplicated skins to use the correct images.
We do not have a tool/function to automate or duplicate the positions from one skin to another.
