The content inside each mesh group doesn't matter either. The thing is the amount of mesh group doesn't matter. So he had to duplicate one geometry in the warehouse tab and assign it to a new cut number so that s4s can read his 4th mesh group in the blender file. And in the package file there were only 3.
UN did that in his tutorial because he had 4 mesh groups in the blender file: 3 of them were the sim legs and 1 was the skirt.
You don't need to duplicate the mesh in s4s.
