Most of these commercial layers aren't designed by their poultry genetics companies to be anything but great layers. Layers with great feed conversion. These are not breeds, of course, these are all commercial, specialized hybrids and are not dual purpose birds, by design.
It is rare that the industry for whom these hybrids were developed, really want a very large bodied bird. 4 pounds would be pretty common and 5 pounds would be an extraordinary stout example.
This data is available on these corporate websites. Tetra, Hubbard, ISA, Hendrix, etc.