This is a stupid post, but it could be a useful piece of worldbuilding.
In my experience success in (sword)fighting hinges particularly on two things:
Dwarves suck at both of those. They are short, their arms are short, their legs are short, they're slow and stocky. Now, of course there are many other factors that figure into whether you can win a fight and dwarves are traditionally considered to have some of those. But in my view the qualities they have should be primarily valued on a battlefield. Discipline, superior technology/gear/weapons, lots of stamina, a stubborn unwillingness to yield or run. They should excel at defense, at formations. They would make the best friggin spearmen.
But in a tournament setup with a one-on-one duel? Not so hot.
Of course your dwarves could be completely different. There is no there, there.