Who was tougher, Roman legionary or a modern spec ops soldier

My opponent appears to make some good arguments, but unfortunately they are not based on facts but rather just a set of hollywood perceptions.Fact #1: During Roman times, the average life expectancy was in the 20's-30's. Most died in childhood, and only a select few survived into their 50's. Weather, starvation, and disease were all major contributors to early mortality. Everyone, rich or poor, suffered during the winter months.Fact #2: Our modern diet is richer in protein. We consume more meats than we have even just 100 short years ago. Romans and Legionnaires all had much lower levels of protein intake. In fact, we have gained as much as 4 inches in average height since the middle of the 19th century alone (Source: http://www.huffingtonpost.com...). The average Roman soldier (from ~500 BC to 500 AD) was somewhere between 5' and 5'6" in height depending mostly on what region he was born in, and whether or not he suffered a famine during his formative years. In terms of sheer physical size, the average Roman is approximately the size and stature of the average 16 year old today, and weighed approx 140-150 lbs. There is a well documented study of over 100,000 soldiers in WWI where the average weight was less than 145 lbs (144.9 lbs, exactly)?!?Fact #3: The average modern US soldier physically is approximately 5'9.5" and weighs approximately 175 lbs according to a 1984 (unknown source) and 2004 study conducted by DARPA. The 1984 figure did not have weights.Fact #4: The most important determinant in a close-combat situation is physical size. An extreme example of this would be a 120 lbs fighter going against a 220 lbs fighter. Obviously, the larger fighter would have a tremendous advantage. This is precisely why there are weight classes in boxing, wrestling, and mixed martial arts - the larger fighters would have an unfair advantage. Based on just the physical differences that exist between ancient Romans and modern people, the fact that Romans had to survive winter famines throughout their childhood, not to mention the occasional famine, I honestly do not believe that a modern SFO would have any trouble at all with the physical aspects of fighting against a Legionnaire.Furthermore, let's not forget the value in standardized training. Today, all our soldiers are taught basic fighting skills. SFO's are taught not only basic skills, but often very advanced techniques plus they are often trained to become trainers themselves (US Army SFO's, for example, are considered "trainer operators"). Not only are they experts in their crafts and techniques, but they are able to teach their abilities to others, including foreign people with limited language skills and technical proficiency.My opponent makes an interesting point: "Roman soldiers that survive several battles".... Every modern SFO is expected to not only survive "a few battles", but to win them, and to retire a few years later. I think this alone speaks volumes about the difference between SFO, who are hand-picked from the ranks of volunteer soldiers, honed over several years through well designed, evolving training, and then released into units with vast combat experience and fighting skill.Compare this to the Roman soldier, who essentially was not much more than a cog in the Roman war machine, who ended up in the Army because of reasons other than volunteering.Based on my careful analysis of physical size and training standards alone do I believe that my case is much stronger for the idea that modern SFO's are better, tougher fighters than Roman Legionnaires.