There is no need of "railguns." Besides, the most effective heavy artillery of WWII was the US M1 240 mm Howitzer, which ruined the day for every "railgun " it fired upon. The M1-240 would be much more useful in the game, but we don't need it either. We have the M4A3-75 mm Sherman, which is all the artillery you should need. Learn to use it well and you will stop asking for the big guns.