There are two reasons y julius is likely to overthrow polo

 the white ~horse~ owned by julius (founder) omen seen in movie provide food for his soldiers who are classified as criminals

the 2nd reason later then tell you, maybe able to save the princess from "luigi"

https://youtu.be/R2AS6JX2UDQ?si=87JxVXYXKyJbMh__

This is what the "new rome" likely to eat

after citizens play roman chariots slot game