I think it would be a useful feature if they allowed you to save custom formations. I think Imperial Glory might have had this feature. It would be easier and save you time if you were able to save formations that you like to use in other battles without having to set them all up again.
For example: If I line my men up in "A" formation, it would be nice if I could save it, and then in another battle where that formation is suitable, I load "A" Formation and it puts my men in it automatically or you can click and drag and they'll be in that formation.
Does anyone else think this would be a nice feature?