I suggest creating a new map for GB with double the length and width (making it four times the size of our habitual maps).
Such a map would make players behave more strategically, and scouting / lighting up the map would become very important, as would be the grouping of forces.
I thought of this while watching some youtube videos on the battles of Leyte gulf, where opposing forces had to do quite a bit of guessing in order to find each other.
If the map size is not limited in order to avoid/limit crashing, this would be a fun mode, don't you think?