It is a joke the filmmakers may not be fully in on - the Romans in Python are analogues for the British, managing an empire and bringing the "benefits of civilization" to "quarrelsome and backwards natives".

And the joke applies almost exactly to the British rule of their colonies. Or do you think Monty Python wouldn't make an anti-nationalist joke?

(The "let's interrupt our program because the Queen has just started watching" is the best.)

Nah, the joke is more self-centered than that--it's the answer to a British adolescent's exam question "Name x benefits of Roman rule." No actual Romans would sit around saying "Wait...this is the same word either way, but is it dative or ablative??" either.

High school historian perspective: I don't know; compare their conquest to the greek's. Greek civilians thought of Rome as "the light of the world," even though their wealth was used in much the same way.

That's the complexity. The Roman invasion did enrich their society (as did the Greek before), yet all none of the dead people got any of it and many individual lives were completely destroyed even if not literally terminated.