You might be interested in some previous threads on the accuracy of the "Deadliest Warrior" series as well as notably different warriors dueling one another throughout history:

• How historically accurate is the show Deadliest warrior? - 3 comments, over 1 year old.
• The commenters do some analysis of a few portions of specific episodes and make some general statements, while one of them links to the reviews of the series done by an SCA (Society for Creative Anachronism) duo.
• Are there any accounts of one on one battles between warriors of vastly different cultures? - 152 comments, over 1 year old.
• The original post directly references "Deadliest Warriors", and examples are given ranging from Russians vs. Mongols and Vietnamese vs. Mongols to duels in Roman times and biblical battles.