The fortress, CMBB_Ax 2960 x 3040

[Extraordinarius]

I personally would use it for an attack or assault of 2000 points or more. (Actually, I'd go straight to 5000 points. I like big battles, but that's just me.) Some fortifications are necessary if you wish to represent the fighting positions of an old fort. My theory would be that in battles smaller than 2000 points the attacker would have an increasingly good chance to outmaneuver the defender because the defender would not have enkough troops to cover all the frontage.