Either comic or movie mersions. Rorschach and Niteowl were allies but they went through quite a rift for a long time before they renewed their partnership to take on Ozymandias, who proved that he was a match in combat for either of them or even both of them at once. But what if things had gone another way and their rift had led to them throwing down and fighting each other? Who was the better fighter?
Personally, I think that if they had ever lost their tempers and let that happen they would have absolutely beaten the crap out of each other to an epic level, and come to a draw. Standing there beaten and bloody, they would have finally come to their senses and said, "Jesus Christ, let's go get a drink or something." (Though Rorschach would have insisted that it be non-alcoholic.)