In a duel with just staves and no magic, I'm going to say that a Mage Hawke would beat a Mage Warden.
As an Apostate, Hawke's had years to learn how to defend themselves without using using magic in public, whereas the Mage Warden only can be said to have learned how to fight after joining the Grey Wardens, since the Templars likely aren't happy with Circle Mages learning combat training.
In a duel with magic however, it's fair to say that a Mage Warden would win hands down.
The reasoning for this is twofold; first because they had formal magical training unlike Hawke, and second because you're said to be Irving's star-pupil (something Uldred mocks you for), so you've clearly got enough of an aptitude that the First Enchanter himself chose to mentor you.
As for the other Wardens, I'd say that it'd probably be depend on the race and class of the Warden in question. A Warrior Hawke could probably stand toe to toe with a Elven and Human Warrior, but I think they'd probably lose to a Dwarven Warrior. Similarly, a Rogue Hawke could probably be evenly matched with a Dwarven and Human Rogue, but probably would lose to an Elven Rogue.