One thing I would implore of people creating their own styles is not to worry about doing something another style already does. You don't know if you'll even use the other one in your campaign after all! That and I think it makes sense for styles to occasionally share features, as different martial traditions will inevitably borrow from each other.
For your other question -- I kinda like both, especially because for a home game you wouldn't be limited by space and so the mechanics don't need to be written "elegantly." Instead of the x-in-6 chance though, I think what I would do is have the player roll an attack and compare their result to the roll of the arrow that was fired. It's not at all simpler or "better" than x-in-6 of course; I just like the flavor of it.