A colleague of mine works in this area, and this topic in particular. You can find his work here: https://www.une.edu.au/staff-profiles/hass/ttaylo33

He'd probably have a more accurate answer than I do, and he's the author of a forthcoming book, Mass Violence and Genocide in the Roman World.

We've discussed this very issue in the past, and based on my memory of what he's said [and he also gave a seminar presentation on this], the idea that a group of people who had committed crimes against Rome should be punished by genocide [attempted in whole or in part] was relatively standard practice. That's not to say it was 'common', but that there are many incidents where Rome punished a people by what we now refer to as genocide.

To clarify some of this [I've worked on genocide studies, but not the Ancient World], it's important to note that the term 'genocide' is used to refer to past incidents also, not just modern. The term was also effectively created, particularly by Raphael Lemkin, to describe that particular phenomena where one group of people try to eliminate an entire group of other people [I'm trying to be vague and inclusive here in my use of the term 'people'] - that can include by destroying their culture, preventing them from breeding, and of course, attempting to kill them. Note that it doesn't need to be the elimination of the target people in whole, it can be 'in part'.

As for evidence, I recall from the seminar I attended that there were many accounts from Romans about their attempts to, in effect, 'destroy' people as punishment. I'd suggest checking out Taylor's work for more detailed references.