By mech, I mean any bipedal war machine of around 22ft height.
We all know tanks are notoriously bad fighting in a city. They lost Hitler Stalingrad, and by extension, the War. Why is this? Is this because their treads get stuck on rubble? Because they can't shoot upwards at attackers dropping explosives from buildings? Were tanks not able to turn effectively? Would mechs be effected by any of these hinderances?
The objective would be to pound the city into the ground, but the military wouldn't consist solely of mechs. There'd be infantry and artillery and air support.
The game is Warhammer 40k, but I'm talking about realism. I like it when a game is backed up with a touch of verisimilitude.
Imagine the attackers consisting of 100,000 men, 2,000 artillery pieces, and 500 mechs, taking on a city 140.3 km^2. Defenders would consist of similar numbers and units. The objective is to pound the city into the dust from whence it came!
Would an enemy defending the city be utterly terrified when they saw a mech lumbering down the street, or would they laugh and employ guerrilla tactics?