Okay if were comparing hawke to the warden the warden accomplished feats that were way more difficult then hawke had to deal with. If they were to fight i think the warden would win fairly easily. That being said both are only humane and both can be killed in the same way. Now the inquisitor seems to have some sort of god given power so by the end of the game she/he will probably be the most powerful person in thedas.
Except that most of the Warden's accomplishments aren't combat-related. Sure, the Warden was essentially a general in a massive country-wide armed conflict, but most of this involved diplomacy as you were trying to get a faction to uphold their end of the treaties. Aside from fighting werewolves, an Archdemon and heck of a lot more darkspawn, the Warden faces pretty much the same enemies as Hawke does.
It's hardly fair to then say that because the Warden did more impressive feats, they'd be better in an actual fight. Consider that in Act 2-3 of DA2, Hawke is sent more often to solve a problem as an enforcer than as a diplomat, Hawke's known for being a good fighter, so that probably puts them about on even in terms with the Warden in terms of martial skill.