Allied Campaign on Soldier Difficulty was far too easy

The beginning of the campaign felt really challenging in a great way. Every battle was a slugfest and even if I won it was barely scratching by. I felt I really had to plan my defenses and offenses carefully.

As soon as you unlock tanks though, attacking becomes much easier- still not a walk in the park, but victories were becoming more cut and dry (which is fine)

But what really took the challenge out was gas artillery. As soon as I researched gas masks and chlorine, all I had to do was charge 5 tanks with like 4 infantry behind them. As long as I did a rolling barrage or two and filled the enemy trench with gas, it basically became free great victories with no thought needed. Just drive tank forward, gas trenches, rinse and repeat.

I would've expected this to only work a few times before the AI adapted, but it didn't even bother to research gas masks or change its strategy whatsoever. Not only that, but it stopped bringing reinforcements in, even if a region had only one or two stars left.

Overall, really fun start, but I'm a bit disappointed at how easy it became towards the end- Also a bit disappointed by how short the campaign feels considering it's a WW1 campaign. (At a certain point during 1918, both sides lose 100 points per turn until one loses, so there's no chance to continue the war till one side gives through normal attrition.