I can definitely say what you have is not recommended, because you're going to be spawning arrows every tick.
If I were to do it, it would be...
On clicked - destroy all arrows
then in subevents
If sprite cows <= 2, spawn rightarrow,
Else, spawn leftarrow
But that depends on what your end goal is. If you can clearly describe what you are trying to do in writing, you'll be able to narrow down what events are necessary as well.