dear Armand
Ah, you have stumbled onto a subject that has been the rage of discussion on Society of Daisy for years.
I will dig up an article I did for this and had published a while ago and post it to your blog. But for here, the short form can be boiled down to this.
1. Figures are tokens, that's all. If you are going to assume some sort of connection between the form of the figure and its prototype, you are assuming more or less, a Platonic World of Real Forms where the toy soldier of a particular period represents a real soldier of the same period, and that the two are connected by the "soldier of soldier" the "soldier beyond which there can be no other attribute of soldiers" in that platonic world. That is, that both the real soldier of say, the English Civil War shares some attributes of "soldier" with his toy soldier representation today. Both may have a set of attributes particular to each, but only some of which are common.
This is a dangerous proposition. If you assume this then through that connection you assume some sort of interconnection, and that ALL of the attributes of each are inherent in the other. Thus, if you have figures of the Waffen SS, while you may use them in battle they share some identity, some attributes with the real SS including the atrocities and genocide. This is an extreme case, but if you are going to assume the connection then you can no longer say with Don Featherstone that when we play our games and fight our battles with our little lead men, we make no little lead widows and orphans."
If you hold this principle to be true, that there is that connection then what of your other great arena of activity here, "Needs more Boobies." If the figures there of scantily clad women sometimes in dodgy poses with weapons,posess a connection with the reality, then the image ( The "Imago Mundi") represents a transcendent reality, and THAT may be at times even more dodgy than the SS
2. If you assume this transcendental connection then you also have to ask what the implications of the game are in the transcendent sense. That is, that there is a reality to the game BEYHOND that which we see in the table top. That is, what are the actions that we make with our real life soldiers here doing in that transcendent sphere? What horrors are we then creating in the "never-never-land" of our games.
Further, if this is the case then a strict interpretation of your theory would mean that for example, if we did not have figures EXACTLY in the form and coloration of the real life, it would not be real. Thus, you could not fight Eylau and Friedland in the Napoleonic Wars without French armies in white.
ON THE OTHER HAND
If you are going to assume that troops are mere tokens, that is, mere tokens of representation, like Pooh-Bah's
"Merely corroborative detail intended to give verisimilitude to an otherwise drab and unconvincing argument" then the sky is the limit. After all, while ones artistic sensibilities might be offended, as the troops are mere tokens, and their REAL nature is the mathematical values (abstractions and arbitrary as they are to a man, the nature of the tokens is unimportant. Though we might like to have real items and it is a bit jarring to not, there is no real ban or prohibition on it.
Of course you must remember that I game almost exclusively in "Imagi-nations" so talking about the necessity of verity is like a Puritan delivering a sermon at an orgy.
For example. Suppose I wanted to use a highly abstracted game like Joe Moreschauser's with mirror armies etc, and all the values highly abstracted into the arithmetic values of a stand. I could make a game of Russians versus Mongols.
"Not so bad you say? What's wrong with that" Nothing, except that while I wish to use Historical Mongols, I wish to use for the Russians, the Russians of 1941. That is, while the "heavy Cavalry" that forms the most potent part of Moreschauser's Ancient Armies, I wish to use Mongol Horse Archers, for the Russians I wish to use T-34's Light missile infantry etc will be allied bowmen for the Mongols and Machine gun teams for the Russians. As the combat values and attributes of troop types on either side for a given troop type are identical, the physical representation used is immaterial.
I grant you the idea is jarring and a bit uncomfortable, but it is logical.
By the way, this is a project I am present working on for fun, but it was done in real life.
A friend of mine who is an iron-worker was on a job with a helper from his crew and at lunch they took to talking about their lives and my friend, let's call him George, explained the hobby of war games. The helper was intrigued and George set up a little min-battle right there with the various bolts and nuts, rivets and parts they used to represent various types of troops. Bolts could fire like cannon and hit if you won the toss of coin. Nuts had no fire but could melee etc. Both moved at a certain rate, and this pile of small steel plates was a hill, and this rod was a river etc.
The game worked perfectly well, even though the representational tokens were just simple pieces of ironmongery with numerical or procedural values attached to them.
To draw in the example to your case, using Romans for say British Colonials is probably just as jarring as Mongol Horse Archers versus T-34's but again, remember that they are just tokens (unless you are going to in effect say our little lead figures have little lead souls in which case you have let yourself in for a world of trouble) then why not. In fact Ral Partha, with their "Rules by Ral" and I believe it was "Chaos Wars" did just that, allowed you to mix all periods from Cro-Magnon to Star Wars in the same game (theoretically).
But also remember, that almost ALL of us did EXACTLY the same thing when we were very young and mixed the cowboys and the knights, spacemen and WWI GI's in our games in the backyard, and in an eerie reversion to "The Game of George" way up on the "high iron" we uses small pebbles for rifle fire, small stones for artillery, and a cinder-block for the atomic bomb.
Those of course were back in the days when we had fun.
As I said, this is all intellectual legerdemain to me, being a person who long ago moved into Imagi-Nations. So in my various armies of the 18th century I have Napoleonic figures I like here and there, 17th century "Lobster Cuirassiers" as Cuirassiers in the 18th century (converted with new heads with Tricornes) Mohawks showing up as Mackattack Indians in the middle of an alleged "German country" and in the neighboring country of Gulagia, a Russianish country whose capital is Gullagin's Island, I am finishing a unit of Chevalier Guards which are 15th century Polish Winged Hussars.
You will remember my defense of breasts on "Needs More Boobies" that these figures on that thread do not represent real figures, but are caricatures -- burlesques -- (in EVERY sense of the word) and satires of normal war games (and war gamers) and as such things that their extremities are well armored but their torso's and all vital areas completely unarmored-- and undraped. Obviously unrealistic, but just as obviously a satire. Thus the armies in Imagi-Nations, burlesques of real life.
The only reason gamers get so adamant about absolute fidelity and realism in figures is that they have an ulterior agenda.