Roman Empire vs the US Army with a twist

We're at a US military base. All of a sudden, some highly advanced aliens come into the base and announce that they have decided to play dice with their lives. The US Army has 24 hours to prepare 20000 people to go face off against the Roman Empire in its prime. They will be teleported back in time and can bring anything that they are holding onto at the moment. It has to be sth that they can carry so things like vehicles won't count.
The fate of the world depends on whether they will be able to defeat the Roman Empire. Defeating means taking control over all of the Empire with all of it's territories. If they cannot, the aliens will teleport Earth into a black hole and humanity will be lost to time and space.
They can choose the people that they will send back, so they can choose a medical team in order to fight the diseases that they may contract. They can take some historians with them in order to have better understanding of the empire and possibly communicate with the common folk. They will have the option to spread into groups around the empire or all teleport into the same place. They will not get to choose where exactly they teleport to, but it will be close to the edges of the Roman Empire.
So, can they do it?