Is Nigersaurus considered a medium herbivore?

So I've always used this type of chart to know which dinos can be in the same paddock without killing one another, and it always worked. But recently I put 2 nigersaurus, 2 velociraptors and one ceratosaurus all in the same enclosure, and the ceratosaurus hunted one of the nigersaurus. I know they are much smaller than the average sauropod (and even eat on small herbivore feeders) but the game says they're large herbivores (the same as the other sauropods) so I thought they would also be fine with large carnivores. Silly question but it really made me curious.

So I've always used this type of chart to know which dinos can be in the same paddock without killing one another, and it always worked. But recently I put 2 nigersaurus, 2 velociraptors and one ceratosaurus all in the same enclosure, and the ceratosaurus hunted one of the nigersaurus. I know they are much smaller than the average sauropod (and even eat on small herbivore feeders) but the game says they're large herbivores (the same as the other sauropods) so I thought they would also be fine with large carnivores. Silly question but it really made me curious.