>>6031945Lots of Titan armor and Marks also have sheathed knives, even though knives have nothing at all to do with their class.
In-game its mostly just there to kind of look cool. Although, in some instances, they go out of their way to make the item actually sort of make sense with the perk on it (like how the Armamentarium Armor has two grenades strapped to it. Even though your character doesn't pull the grenades off, its still nice aesthetic "continuity.")
