Actually, even better ...
Scrooge as a Green Lantern (yes, he's greedy as hell, but he also has hellacious willpower) versus Flintheart Glomgold as an Orange Lantern.
THEY WOULD TOTALLY BE LIKE HAL AND SINESTRO.
(Although imagining the Finding Nemo seagulls all wielding Orange Power Rings and saying, "MINE! MINE! MINE!" as they fly into battle? Is AWESOME.)