Hi,
Are you planning to put in the unit card more information than in vanillia? For example, the number of arrows, spears, horses used type (light, heavy). It will be helped on the battle field.
And second thing.
After moving the mouse on the unit on the battle map in RTW showed the extensive information about its status, in MTWII it was very simplified. Do you will use version of MTWII or RTW?