That'd be fine. The "barbarians" are just the mainstay of the enemy horde. They might use all kinds of beast, from rabid dogs to enraged hippos - or fantasy-based animals. As for magic, I don't mind it either way, but I myself always aim for nitty-gritty sword and shield work. Whoever wants to cast a fire ball may do so, just be careful the barbarians don't suddenly show up with shaman to launch lightning bolts at you!