"Huge maps, based on real terrain. The maximum battle size is about 15x15 kilometers".
15x15 is Huge ? check out BCT/ATF and you will see huge maps with lowest level unit is a single team/vehicle
Based on the description I assume that you are trying to compete with battlefront titles ?
15x15 km is the maximum scenario map size. The scenario and campaign battle locations are picked from much larger master maps. I try to avoid mentioning the actual sizes, because they may be subject to change. It's always a question of detail vs size. In AB you can have a 15x15 km battle with hundreds of units and are able to zoom in to see the individual men, casualties, tank commanders etc there.
Personally, when it comes to the actual game, I'm not trying to "compete" with anybody. I just wanted to make a game I like to play. The ATF series was a major influence to me by the way, and the old Combat Mission games too. Now with Matrix we're maximizing the game's potential, with special emphasis on the graphics and UI, as I see it.