are tabs supposed to have the backing leather separated from the cordovan?
Mine does and I use a Bateman tab.
That is not a requirement by any means. Many prefer not to have that and just use the one piece. I build mine with the extra backing because it feels better to me.
There are quite a few different pads out there, but multiple layers are common and most do not glue the layers together but leave them separate.
Mine do have the separat layers.