The Topic Creator was talking about a duel. Who would win in a fight, not a field battle.
Then again, my opinion is based off of an entry in his SGZ biography that used to exist, but disappeared. This entry mentioned how Lu Bu raided Cao Cao's camp at night, and Xiahou Dun led the defense, which lasted long after Cao Cao retreated to safety, Lu Bu finally retreating at dawn.
In the novel, this is intensified with Xiahou Dun and Lu Bu fighting each other in a duel until dawn.
Now, ignoring the novel, we still have one warrior's prowess against another, and neither faltered. Because of this, I've always looked at Xiahou Dun as dedicated and physically powerful, though certainly not the better general (but certainly the better governor).
However, I must say again, the only proof I had was that one statement that was formally in his SGZ biography, and then disappeared. I know not where it went.
"Because he has died, there is no more room for death in him." -- Lao Tzu