Speaking of armored trains, having them in the game would make sense only if we have maps covering the German invasion of Poland, in september 1939. At the time they were already considered obsolete, but that's the only period of WWII when they were extensively used in combat.
Fun fact, polish armored trains used in the September Campaign (some of them with improvised armour made of sandbags only, some of them being from pre WWI era) proved extremely successful, destroying or damaging dozens of armored vehicles, shooting down three aircrafts, and inflicting substantial losses of the German infantry.
It was a big surprise for both Polish and German generalship and it actually prompted Germans to reintroduce armoured trains into their army