How about that all tanks are cheaper by half. So that you can make every battle "Kursk battle". Lot's of armor clashes and AT guns,or at least that some maps have cheaper armor,for example: "The Battle of Prokhorovka" map.
I think must be exactly opposite.Cost for tanks to be doubled,and artillery to have the same number in models as tanks,with far less price.The number and cost can be different from one faction to another.Battle between tanks can be funny,but after a while became boring.Reproducing every phases from the real war,with artillery barrage,infantry assault,battle between tanks for taking the flanks,intervention of planes for supporting them...that will be far more fun and interesting.Having just few tanks,who sit like ducks(more or less) shooting each in other,is pathetic.