I've modified the "Numbers.bmp" file to allow display of Army Group and Theater unit sizes. I then edited my "Germany 1945 (Last Stand)" scenario to use it. I put the modified "Numbers.bmp" file in the graphics sub-folder for that scenario, then edited the unit sizes for all the units in the scenario as follows:
To Display ----------- Use
Theater --------------- Army
Army Group --------- Corps
Army ----------------- Division
Corps ---------------- Regiment
Division -------------- Battalion
Brigade -------------- Company
Regiment ------------ Platoon
Battalion ------------- Squad
Company ------------ N/A
Platoon --------------- N/A
Squad ---------------- N/A
Note that the smallest unit size that can be displayed with this Numbers.bmp is the Battalion, and it will be indivisible. Company, Platoon, and Squad unit-sizes can't be displayed.
Also note that the use of the Brigade size is skipped. You can use it and it will display a Corps, but if subdivided by 2, the sub-units will be Corps. Also, note that units displaying the brigade units size will subdivide into regiments, regardless of whether they are divided by 2 or 3. And, also, units displaying a Division unit size will subdivide into brigades whether they are divided by 2 or 3.
Finally, note that the smaller unit sizes may rebuild faster, since unit size impacts rebuild rate at the smaller sizes.
In the attached screenshot, units circled in Yellow are displaying the Army Group size; units circled in Red are displaying the Theater size.
The actual Numbers.bmp file has been posted in the Graphic Mod thread in the Scenario Design forum.
