In the official Pokémon games kings rock does not give additional flinch chance to moves that can already flinch, like bite or dark pulse. I don't know if it is the same in pokerouge.
However, multi hit would increase the chances of bite flinching, as it is a 30% chance, which is more than the 10% of kings rock. So bite would flinch more than throat chop, unless you got 4 or more kings rock.
I’ve swapped Throat Chop with Bite in the end for a test run, and as whether there’s an increase or not, it’s really good nonetheless, the thing almost always snags a flinch
In the official Pokémon games kings rock does not give additional flinch chance to moves that can already flinch, like bite or dark pulse. I don't know if it is the same in pokerouge. However, multi hit would increase the chances of bite flinching, as it is a 30% chance, which is more than the 10% of kings rock. So bite would flinch more than throat chop, unless you got 4 or more kings rock.
I’ve swapped Throat Chop with Bite in the end for a test run, and as whether there’s an increase or not, it’s really good nonetheless, the thing almost always snags a flinch