Wow....that's a big meat eating critter.
Hard to say if Leviathan and Megalodon would have "fought each other for ocean supremacy". They sure would have crossed paths. One was probably the alpha predator when comparing apples to apples, full size male to full size male, but they would have fed on each others young and the like if opportunity presented itself. For both of them to evolve and both to die out, they probably each had a certain niche in the food chain and it could very well have brought them into competition with each other for food. They survived along side each other just like today's Orcas and Great Whites and just like today, a few sharks became whale food and maybe a few whales were on the sharks menu from time to time. Would have been a sight to see though... from a long friggen way off ....those two deciding to have a go at one another...
