A warmouth might. The trouble with sunfish and pickerel together, especially in a smaller tank, is that it's easy for the sunfish to outcompete the pickerel for food. But the warmouth is more pickerel-like than any other sunfish; it likes to hang back, bide its time, and let the food come to it.
That would definitely be an interesting tank. Just be sure your stock are very close in size. Pickerel and warmouth both have very large gapes and may try to swallow their tankmates if they get hungry. I once kept a juvenile grass pickerel with a green sunfish about half its length; eventually the pickerel tried to take down the sunny, killing them both.