I won't say it's an 'easy win,' for a human it's definitely a lot harder the bigger they get because the bigger they get the more resistant they are to gunfire. But for most smaller animals that they usually prey on, like antelope and zebras and stuff about that size, it's a disadvantage for the crocodile if it gets too big because it can't move fast enough to keep up with how agile they are.
At that point they have to change up their hunting strategy and have to go for animals that are bigger and less agile, like hippos. Or cannibalism: