If Vlad was a vampire why would he fight with a sword?

If Vlad/Dracula was a vampire (which they were obviously hinting at without outright saying it) shouldn't he have basically been able to destroy the entire Turkish army without even breaking a sweat? Why would he even waste his time in a sword fight? I also got the impression that the other members of his order were supposed to be vampires too, the way he said there were only 11 of them (what would be the point of showing up with only 11 men to fight thousands, unless those 11 were more powerful than regular men), so even the entire Ottoman empire should've been nothing to 12 vampires.