The Romans fought both in Marius' day, though one at a time. The German descent into Italy could have led to the sack of Rome, but the pirates were a menace to trade and prevented food from being shipped in, which in turn could have led to wide-spread famine. Marcus Gratidianus' father died fighting the pirates with Anthony, Marius executed his other nephew during the German Wars. Anthony the Orator and Gaius Marius may well have quibbled over which was the more formidable adversary - now we shall have a chance to find out once and for all.
German Navy joins hunt for pirates off Africa - The Local