No they are not, but the differences are slight and can typically be altered to fit. You get straight and banana-shaped pads. Either fits best in same-shaped shoes but can be forced to fit. Then, the retention mechanism differs. Some use a little screw, others use a type of spring pin. The one requires a groove in the rubber, the other an indentation or nothing. Again, with a knife, you can make it fit.
Shoe type differs too. Some shoes have a smooth stem, others have a threaded stem. But it seems you want to keep your shoes and just change the pads.