rear brake shoes/drum eventhough self adjusting can only adjust so much.

but if your drums are out of spec, sure you can throw in a new shoes in and the rear brakes will work but at some point in time, your shoes and out of spec drums will not meet anymore and then the front brakes will do most of the work.
i fully understand the percentage of work between the front and rear brakes as i am ASE certified on this area. I work on brakes very often as well.

about calling the brake pads makers, sorry i dont go that crazy to do a research just on brake pads.