The Dacians at their height should do quite well against the Huns. Dacia itself had lots of forests and rough terain, good for defense against a cavalry based force. Besides, the Dacians were allso good at building fortifications, ant their army did honourably well against the Romans, and even won a couple of victories.
The problem will be how long Dacia can stay powerfull, as it had trouble staying united in OTL, and if left alone risks collapsing from infighting before the time of the Huns.
Fun fact: There was a Romanian historian (I don't remember the name) who said that the Romans made a mistake to destroy the Dacian kingdom, because if left intact it would have served as an obstacle to the Barbarian invasions, thus preventing the fall of Rome itself.