what the fuck are you talking about man, the chinese used nun chucks to beat down their rice and shit
but as for the question, depending on the vikings skill with bows it would still most likely be ninjas, although the vikings got strength, ninjas are ALL assassins, they know how to creep leap and slit throats all stealthy n shit, granted a viking could take out a few ninjas with just one swing of an axe, ninjas aint fucking stupid, theyd know that getting within 7 feet of a 6ft whatever brute with a 5 ft axe aint a good idea, but it really just comes down to numbers and the plain fact is, ninjas were small seclusive societies with not many in a group, and vikings rolled with serious numbers