[runequester]

this comes up when fighting the polish too, or early war soviets a lot.

Artillery, loads of it. Even mortars can do a good job killing untrained grunts in the open, but you have to ensure you keep pummeling them with it. 1-2 turns wont be enough.

Don't be too worried about the odd shell falling too close. Your guys will really quicker.

MGs are great IF you can find a place behind the line where you can deploy them. They tend to get picked to pieces if they are within easy rifle range though

Also, consider some armoured cars or light tanks. They can draw infantry fire well, and it'll take them a long time to deal with them.
In actual urban combat, they aren't so hot though.