formations is not magical.
it's just a mapped key, usually with a few steps, that you press to move characters. using it during fights might lead to you having toons all over the place, not sure I'd want that.
When I played 4 ranged and a tank, I used to stack all ranged and just move them when something was on the ground (using arrow keys to "move others"). if there was something that made one of them go boom, i'd usually just soak it like a boss