Oh hmm. Maybe Marauder is the umbrella term and then there are specialists underneath depending on where you're from and what you're stealing? ( viking, pirates, raiders, bandits, etc)
Shameless bump as we get closer to update
Hammers are already in the game, but as tools for Disciples of the Hand, not weapons (specific types of hammers are used for BSM, ARM and GSM, the later being the reason Godbert Manderville uses one, being the owner of the GSM's Guild and everything). And as others have already said, 'Viking' is already essentially what MRD/WAR is, right down to having Berserk as an ability.
So I really don't see this being added as a class, especially as it was never a particularly common Job in the FF series (only appearing in FFIII and V, the later renamed as Berserker) (but hey, I've been wrong before!).
+1 for a job using maces.
Or a job using a one handed axe.