Final answer:
The question poses a factually incorrect scenario; Julius Caesar, Spartacus, and Augustus are figures from ancient Roman history and have no connection to modern rugby. Instead, their significance lies in the political and military history of Rome.
Step-by-step explanation:
The question regarding who led Rome to victory in the Rugby World Cup championship is factually incorrect as none of the historical figures listed (Julius Caesar, Spartacus, Augustus) were associated with the modern sport of rugby. Instead, these figures are significant within the context of Roman history. For instance, Julius Caesar was a late Republic statesman and general who waged civil war against the Roman Senate and declared himself dictator. He was known for his military campaigns in places such as Pontus and not for sports achievements.
Spartacus was a gladiator who led a significant slave uprising against Rome, and his revolt was eventually crushed by the senator Crassus and Pompey. The members of the First Triumvirate, an important political alliance in Roman history, were Julius Caesar, Pompey, and Crassus.