Whether the
Res Publica Romana was a conscious imperialist or not is a question still being debated (Imperialist or "Stumbling-into-empire). These two represent each extreme in the opposite viwpoints
Badian, E.: Roman Imperialism in The Late Republic, Oxford, 1968.
and
Harris, W. V.: War and Imperialism in Republican Rome, 327- 70 BC, Oxford, 1979.
With most others in between, for example
Beard, Mary & Crawford, Michael: Rome in The Late Republic, London, 1999.
My own point of view is that the Roman constitution forced young patricians into searching for military glory in their Cursus Honorum, but I have elaborated on that elsewhere and even quite recently.
But my point is that whether or not the enemy had provoced them or not, in fact especially if the enemy had provoced them, the Romans did not treat war like a game or in a sort of chivalric manner. The Romans were very practical and very brutal. When I put the timeline online, you will see many cities with "Exterminated", so play as you want to, but be aware that you are playing ahistorically if you have Romans acting like chivalric Kings in the Middle Ages. If so it is indeed SwissBarbarians, not Romans.
But whatever ticks your dicker is fine by me, enjoy your own style

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