If you wanted to be bitingly cynical, you could make a movie about the deficiencies of vanilla RTW combat...

"A Day in Teh Life of a Roman Soldier" or something. Using voiceover, cover the [mis]adventures of a simple hastatii as he fights the dreaded Elephants of People-Punting, the terrible Chariots of Death, and the futuristic Ptolemaic Terminators (those darned Egyptians). Sadly, the list can go on with an "ETC".

Please share the movie when it's done!