they are allelic. Leopard and pied work very well together.
For sake of precision, what is called a "leopard pied" is in fact a "leopard het pied". And when bred to a normal, 50% of its offspring will be leopard, the rest will be guaranteed het pied. and when bred to a pied, you get 50% leopard pied and 50% pied.
Its similar to toffee, albino, and the combination, toffino, which is a het toffee het albino genetically.
What im most curious about is the super leopard. Can we be absolutely sure it exists, and not just leopard pied? Is it proven out? Are there maybe known health issues with the super form? it could be that its truly dominant, so that the super leopard doesnt exist because its lethal, like it is with spider or pinstripe.