I think this is a common fallacy even among those who know better: to assume that by virtue of his gender, a man is likely to have fighting skills or experiences. Certainly I don't think that the average man has any experience falling (where would they get that?).
Boys do tend to play differently than girls. So it might be plausible to say that an average twelve year-old boy might have more physical skills than an average twelve year-old girl. But translating that to a population of post-college adults with mostly sedentary jobs? Risky at best.