Ah, the quote by quote response, truly the height of civilized web discourse.
"What precisely makes the Umenzi not "central players?" Why must there be Central European factions which take precedence over all others?"
The fact the original crop of armies were obviously European and they are clearly African based. Obviously by European and African I mean their "fantasy world" equivalents but you can tell simply from their dress and armor, or lack of it, that the Umenzi are clearly from a very hot region and possess domesticated animals (war elephants) that are not staples among the armies of their foes. Again if you want to find some explanation that would mark them as being from a geographical similar region again fire away.
I think you are still clinging to the idea that Battleground is superimposed onto a map of Europe, perhaps because GW did it (though whether they did it out of cunning or laziness I've never figured out). I think any prospective fluff is much more interesting if you try to work with the weirdness of the setting and figure out ways to make it all work together rather than marginalize factions because they don't hold to an extant world view which is based largely on the name of one faction.
Try to picture a setting where Hawk and Umenzi territories could intersect. If you want to stick to the Europe-Africa scheme, just stick a decent land-bridge across the Mediterranean and all of a sudden the Umenzi are next door neighbors. Or take a historical example of two cultures from radically different origin points that wound up face to face: The Muslim conquests of the 8th century (too lazy to double check that's the century I mean) when France and Moorish Spain went toe-to-toe for years.
"You seem to hold the view that Battleground has a very specific setting and releasing new factions that don't pertain to your own mental picture are damaging it. " 
My views on the factions are based on what the designers released so far not any kind of mental picture of my own. I certainly wouldn't have opted for the initial factions as they are now and I wold love to see a bit more originality and flair in the design of any further factions. However, for whatever reason the designers picked the starting factions they did and I think they should fully flesh out their initial factions before getting too far ahead of themselves. It has nothing at all to do with my preference for what the world should contain (ask me what new factions I think they should add and I'll tell you), they could have started with were-rabbits and moomin and I still would say "flesh out the originals before adding factions from other regions".
See, this is my point. These factions might be based on real world cultures that are distant from each other, but there is nothing preventing the Battleground versions from living near each other.
Besides, there's nothing that says that orcs or undead are necessarily European. I mean ghouls are originally Arabic, zombies are originally Haitian, and catapults formed from the reanimated remains of a bisected giant are from the twisted minds of the YMG team.
"the game can just be a tactical exercise"
Why is it that the people say this and then seem to get bothered by the introduction of an established lore? By your own rational you can simply use the mechanics and any units you want to make your dream game. The existence of background setting doesn't mean some Lore-policeman is going to come to your home and physically force you to play the game in a specific way.
When I said "the game" I was referring to the specific match up of a historical army and a fictional one, not the game in terms of Battleground as a whole, though I can see how that would be confusing. The point I was making is that you don't need to have a backstory rationalization for every battle. You seemed to be against historical and fantasy factions fighting due to the incongruity of the backstory. That's like having an Optimus Prime action figure and a He-Man action figure and not having them fight, even though they have the same scale, because it isn't in continuity. Wow have I been up to long.
You can make fun backstories for Fantasy Vs. Historical games, it just requires a sense of playfulness. Varus and his legions stroll through the Teutoburg forest when Orc Marauders burst from the trees. The Roman invasion of Britain stymies when the Elves return from Tir Na Nog or where ever and tell Caesar to step off. A necromancer declares that the rocks thrown by his giant catapults will block out the sun. Leonidas responds that he will fight in the shade.
"But if the clockworks are the constructs of another race, particularly a highly magical one, it holds up. Magic seems harder to reverse engineer than early industrial technology."
Wouldn't that make them simply golems rather than clockwork robots? In either case they seem to be the equivalent of the Warforged that wizards of the coast introduced to further stripmine the D&D legacy? I wouldn't mind so much if they were magical automatons, though I'd rather see them be non-sentient units serving sentient masters. Its more the idea of wildly differing tech levels with an absence of proliferation that bothers me. The designers have already established the initial factions as being at a typical Middle Ages level of advancement and as such I would hope that even arquebusiers aren't introduced as units for any faction.
I guess those might technically be Golems. The difference between Golems and clockwork robots is kind of nebulous, and really depends on one's own personal definition. I guess you could take the Golem back to its roots as a clay man given life by Rabbi Loeb. I'm not too familiar with the Warforged, but aren't they mostly humanoid constructs? It seems to me that there is plenty of room for development in strictly human forms, or along the lines of Clanks and Constructs from
Girl Genius. If you have a decent reason for why the faction's technology hasn't spread to the others it can hold up. If they just randomly have guns, then I agree, it's weird that no one ever picked one up after a battle and tried to figure it out. (Granted goblins have gunpowder of a sort but we all know how well that works)
Warhammer btw isn't a steampunk world, as far as I remember any steam technology was incredibly unstable and only used for military use in the form of still experimental weaponry that was apt to frequently kill its users (don't quote me on any recent changes though, I'm far from up to date).
I didn't say it was steampunk, just that there is steam technology extant and it isn't very logically distributed or utilized. I think
THIS sums up Empire technology pretty well.
Hmm, perhaps I should close with something actually to do with the original topic. How about giants? Like the kind that always get cut in two to make undead artillery. I bet they'd love a little pay back
