An interesting discussion going on at AskReddit about the comparisons....
Let's say we go back in time with a Marine Expeditionary Unit (MEU), since the numbers of members and equipment is listed for our convenience in this Wikipedia article, could we destroy all 30 of Augustus' legions?
We'd be up against nearly 330,000 men since each legion was comprised of 11,000 men. These men are typically equipped with limb and torso armor made of metal, and for weaponry they carry swords, spears, bows and other stabbing implements. We'd also encounter siege weapons like catapults and crude incendiary weapons.
We'd be made up of about 2000 members, of which about half would be participating in ground attack operations. We can use our
four Abrams M1A1 tanks, our artillery andmechanized vehicles (60 Humvees, 16 armored vehicles, etc), but we cannot use our attack air support, only our transport aircraft.
We also have medics with us, modern medical equipment and drugs, and engineers, but we no longer have a magical time-traveling supply line (we did have but the timelords frowned upon it, sadly!) that provides us with all the ammunition, equipment and sustenance we need to survive. We'll have to succeed with the stuff we brought with us.
So, will we be victorious?
I really hope so because I really dislike Octavian and his horrible family. Getting Atia will be a bonus.
I think running out of ammo would be the most significant problem. How would the MEU fight a Legion on it's own terms? What about diseases from that era and diseases we bring forward? Food? We'd have to take on the Legion's own methodology of growing and raising our own food supply. I think militarilary it's a huge win for the MEU in the initial fight, but logistically, they'd be in for a helluva time once the ammo is gone.