The different armies of the Dwarven Monarchs. Each has their own unique style, but overall there is a consistent style that is kept in-tact. Dwarves do not vary their armor for different types of units.
Longbeards are the oldest and most experienced of the Dwarf warriors, a fact evident of their long beards. They ensure that they receive complete respect from other dwarfs, who are taught quite rightly to respect their elders.