You don't want anything with a delay.
It is fine to go with a round robin effect, where push 1 = shaman 1, push 2 = shaman 2... etc.

But everything has to be a direct result of you pushing or releasing a key or a button with the effect occurring as you push or release.
This is the distinction between using software to multibox and using software to bot; whether it is attended botting or not.