Avalanche's design notes on the Marak and Rouleau tanks in the August 4th Daily content call to mind 2 tanks that would be great to see in a 1919 module for Infantry Attacks (assuming the war soldiered into fall of 1919 at least.) It would be great to try out the tactics of the Grosskampfwagen and Flying Elephant on the battlefield.
K-Wagen
https://en.wikipedia.org/wiki/K-Wagen
Flying Elephant
https://en.wikipedia.org/wiki/Flying_Elephant
Two K-W's were seized at the factories by the Entente powers. The flying elephant was designed but never flew. Both would have seen combat in 1919.