I really don't want to have to say this again, but:
Gameplay trumps realism.
To my observation (since the only Star Wars I've read/watched are the Movies, some games, but games all set in the movie era, and some of the online Wikia), some of those factions are quite different and deserve independent civs. The
Old Republic and the Empire are two totally different factions. One was committed to preserving peace and had no standing army (for some time, anyway), at least until the Clone Wars. The Empire was committed to building massive armies, weapons of mass destruction, and conquering people. Personally, I'd make the Imperial Remnant, Empire, and New Empire all one faction, with different leaders who affected the game different. Palpatine is a really evil leader and you play him like the Emperor. But Pellaeon is a better leader and more peaceful-ish.
Rebel Alliance is also completely different then New Republic. Rebel Alliance, for the most part, is a an underground movement of freedom fighters, constantly on the run from the Empire, at least until Endor anyway. Whereas the New Republic is a galactic government trying to rebuild the galaxy. Sure, technically one built the other, but the civs have different motivations.
Why would it "be odd to have them on all one map"? Maybe, yes. But Civ 4 runs into this issue all of the time. Then again, you get the occasional argument that America doesn't deserve to be a civ...
Anyway, what you describe is only doable via Rhye's and Fall of Civilization (era specific civs). Which, before you ask, would require a lot of work. A new DLL, for one, and would require specific scenarios (and what we are doing is using a random map). Now, if you wanted to make (or if someone wanted to make) an RFC-Star Wars modmod for this, where that's what you implemented, that would be fine with me. But I'm not going to commit to doing that- maybe after the mod's released, but not now.
I'm sorry if I gave offense, I wasn't trying to. But
please understand that gameplay is more important then "realism". Here's Kael's "HOW TO: Design a Mod" guide, explaining the issue:
1.2 The Danger of Flavor:
Why do games based on movies and movies based on books always seem to be bad? There are exceptions, but we are usually disappointed with the results of these conversions. The reason is that the design of the new game or movie is based so strongly on the flavor of its source that its own functional design suffers.
At some point you should look at your mod as just a functional process, a board game without any stylized components, an exercise in mathematics. A game must be enjoyable at this layer to be fun. Some games are so well designed they only exist at this layer and are still amazing to play (chess, othello, tetris, etc). But a game that has incredible flavor but no meaningful functional elements will always be a bad game.
If you fall in love with a concept that seems like a great idea, but doesnt have any functional value, the temptation will be to come up with a functional need. There isnt anything wrong with this, some ideas come from flavor, and some come from function. Different people are more apt to think from one end or the other. But, be aware of the danger that designing from flavor presents. If you arent able to come up with an elegant functional need you are best off to remove or change the flavor rather than let the functional design suffer for it.
This danger is even more prevelant when you are basing your mod on a known source. It is nice to already have all that flavor developed for you, but it can be as constraining as it is helpful. You will either have to let your design suffer (to what level is up to your own ability to find creative elegant solutions) or be willing to step outside the bounds of the source material and develop new elements, or exclude elements despite their existence in the source when the material doesnt improve the game play of your mod.
