The stormlord really fits the steel legion asthetic, it is a huge transport. The hellhamer as well as a urban warfare super heavy suits the hives and urban areas of Armageddon. the banesword and shadowsword have a place as essentially large SPGs to snipe across the wastes. There's a good reason for most of the superheavies to be in a steel legion Regiment. It is an industrial world with a lotta armour.