Well, I'm just a newbie, but I've already seen several cities in Combine with names which were taken from non-SW sources, or are clearly just plain jokes.
Personally, I prefer those to the cities that are just named "Planet G-2," "Planet G-3," and so on.
It appears that those members who manage to put a city together have a lot of liberty in what they label it. I think we could consider that to be part of the designer privledges.
I, too, value the sense of realism that comes from well chosen or appropriately creative city names. Many of the ones found in SWC really ARE like that, and it's nice to come across them. Still, you can't expect total continuity in an environment like this. Nothing's perfect.
You could justify it as simply one of those things. You know, like Luke Skywalker's name: "Skywalker" can be taken as alien/futuristic, but "Luke" is amazingly just like the common Earth name derived from ancient Greek/Italian origins. I'd advise you to just assume that it has all been translated into Earth terms, to one degree or another. That''s what I do, anyhow, so it doesn't bother me: I still really get into the overall fantasy here.
"When one is at harmony with the universe, one acts as one must to maintain harmony."
-- "The Force" Chapter Six, Star Wars: The Roleplaying Game,