Coach -- just one more thought after Bill's great answer and your next idea. Personally, I would wait until the largemouth bass are reproducing in your pond and then I would add the adult pumpkinseeds. Let the predators get established before you challenge them with one more panfish species to control. If you happen to be in a part of Michigan where redear sunfish will survive, you can have less concern about their overpopulation because they have a lower reproductive capacity than pumpkinseeds.
