If you have graphics-high-end then you can view perfect all the layers. The people with graphics low-end can view perfect only the layer 0, Overall, Dress.
Then the layer 0, Overall and Dress (Easy) is universal to look, for all people.
The layer 0 have the maximum quality of 4096x8192 pixels, same as the other 3 layers specific for graphics high end .
The layers Overall and Dress (Easy) have 2048x4096 pixels.
This solution was as an intention to make the body usable and viewable for all people according to decision from each user.
For all layers is posible to wear various of the same layer, if one is top and other is short, then not problem, but if one is pants and other is short, SL dont know the order and can change the order arbitrary only in this case when overlap the textures.