It would be nice if we could get a formation update button. If you select you're infantry battalion, for example, then click the update button, the engine would look at the unit series, and replace on a one for one basis the units in that batallion with the ones at the top of the unit series. This would save having to replace every element in a formation indivually. Some adjustments may have to be made to the formation, but this is much easier than replacing every element by hand.
I'm referring to the formation template, not an existing formation.