The bullfrogs are the big carnivores, and sure, maybe.

Snakes are active but I doubt they eat nearly as much as the bullfrogs.

Apparently if you introduce a large fish species to your pond, the bullfrogs will not eat them, not sure how you would secure the eggs though. Maybe some sort of area that could shelter from them, but once they come out of shelter when they hatch, its kind of the same problem.

Could also introduce fish that will eat the frogs to keep them under control. Or just leave it all as-is.