Would a "save your formation" feature be good?

I find often that when I'm playing campaign and reaching a point where I have the army I want, that I always have it in the same formation. But if that formation is complicated, it means I spend an extra minute or two every game setting up the formation anew.

Would it be feasible and/or good to have a feature where you could either save a formation and then press a button to use it, or that every new battle automatically sets up your army with the last formation you used before a battle started?

I would like to hear what the veterans think about this.