I once had the opportunity to observe a US Army Ranger class being tested to determine which of them would graduate and earn their ranger tab & beret.
The Roman legions had nothing on any of those guys.
Many of our SOF units, of all services, could give the a run for their money.
The Roman Legionnaires were a well trained and highly skilled and the best of their time. Their tactics I think was what also helped them conquer ‘their’ known world and defend the Empire.
The PJ’s I worked with in USAF Air Rescue were the same way. Their idea of fun was to fly 15 miles offshore over the Gulf of Mexico, do a free fall jump, and then swim back to the base.
To compare a soldier of today with one even 100 years ago makes little sense. Today a soldier has to know how to operate a GPS, thermals, NVGs, sat com, understand the fundamentals of NBC, maybe parachutes in, or he drives around in an armored vehicle that alone is a complex machine, etc etc etc. Todays soldier has to be more well rounded and smarter than ever before, while in the distant past he was nothing more than a weapons carrying platform, a guy that took orders and formed up a line, even shooting on command when told to do so. A continental soldier and a mule had a lot in common.
A soldier today has to be proficient with an AT4, Javelin, M9, 249, M4, 240, various mines, he has to operate radios, know First Aid, understand how to conceal himself from GSR and IR systems, maybe how to deploy CAS........ The problem with all these comparisons is simply that the best soldiers out there are those that have the best "mix" of overall characteristics. Physical fitness like rifle marksmanship are but two very limited aspects, and like a car that has a high top end or accelerates well but can be an overall poor sports car, these aspects alone do not make a good soldier. In some places they lay a lot of importance on hand to hand combat, is that really the end all when other aspects are neglected?