My assumption is that the 200mm is 2m long (size modifier +0~ish). As the missile got bigger the damage progressed following the diameter (under the same proportions 1:10). So even if the missile got 8x bigger in mass and volume, the warhead which proportionally got bigger only increased in damage by x2.
So here is the stats of the other missiles with these assumptions. Note that from these calculations, there are 176 missiles in 1Dton (500cubic feet or 14.ish m^3) if you see anything wrong please correct me.
|Diameter in mm||Length in mm||Size||Area of Circle||Volume of Cylinder in mm^3||Vol. of Cylinder in m^3||Volume Variance||Diameter Variance||Mass (Tons)||No. per Dton||dice||dDmg Average|