Can you think of more then one example to justify making an entire new page?

Yeah, generally the wiki frowns upon additional pages that are just The Same But More of an existing trope.

Actually, Imperium is a Latin word which, in a broad sense, translates as 'power'. In ancient Rome, imperium could be used as a term indicating a characteristic of people, the wealth held in items, or the measure of formal power they had. Maybe, instead of listing it as an even bigger and more amoral/immoral empire, we could have some sorta trope that identifies the main superpowers in a show? Like, for Warhammer, that would be the Imperium, Chaos, Orks, Eldar, Dark Eldar, Tau Empire, Necrons and Tyranids, while Star Trek overall has the Federation, the Klingon Empire, the Romulan Empire, the Dominion, the Borg and so forth.

Actually, we could add Imperium as a 'second' type of The Empire, where it's genocidal, theocratic, racist and zealous, topped off in that, instead of conquering, they eradicate. Sound fairer?

Except not all Imperium's are like that. In Dune it has tendencies toward that but gives an impression of world-weariness rather then zeal. In Traveller none of the three Imperiums were like that though all committed atrocities from time to time.