When I started wargaming (in 2005), I wasn't interested in history as much as I wanted to play with toy soldiers. But, I have found that at least some historical knowledge and even fictional knowledge (e.g.. Beau Geste, Sharpe's Rifles, Saving Private Ryan, etc.) of the troops involved makes the whole enterprise that much more enjoyable, especially if it can somehow be translated to game play to make each side distinct in abilities. While I haven't read extensively with this focus, I do make some effort to learn a little here and there. The details I pick up help me capture the flavor of the period as I understand it, which aids in my immersion in the game.
Recently I took to cobbling together some home-brewed Victorian/Colonial adventure rules (I consistently place Victorian sci-fi in my top gaming interests ). They are fairly generic, inspired by and borrowing from G.A.S.L.I.G.H.T, Soldier's Companion and an untold host of free rules on-line. In the present incarnation, troops are simply classified as European or Native. My intention was that they would be differentiated by special abilities/characteristics.
For example, La Légion étrangère get a +2 on their willingness to charge and +1 on their morale rolls, while Lizard Men warriors armed with swords and clubs (my Legion is often sent by France to either Venus or some "lost world" island) get +1 on their movement and +1 on their melee attacks. Those armed with bows or throwing spears do not get the melee bonus.
La Légion étrangère: Bonuses and Penalties
- Drunk - apparently drunkenness was rampant in the French Foreign Legion. This seems more individual than unit oriented and I try to avoid individual modifiers for members of a unit save for officers, unless it's obvious from looking at the mini. It's just too easy to overlook when I'm caught up in the game . On the other hand, I could justify unit wide drunkenness on the grounds that they all spent the night tying one on in the nearest settlement.
- Desertion - Desertion rates were perceived as high but seemed to vary based on the locale and whether there was a suitable place or enemy to desert to. I would implement this after setup before the first turn with a roll to see if and how many individuals desert, potentially leaving me with a weakened force.
- Impetuous Charge - more than once, legionnaires charged an enemy in spite of orders not to. I would probably add a rule such as "if finishes movement within charge distance, roll a check to charge, and if pass, charge the enemy." This takes some control out of my hands, and as a solo gamer, that's a good thing. Plus it's in character for the Legion.
- Veterans vs. new volunteers - either in addition to other bonuses/penalties or combined into a package. The latter are more likely to desert, to be incapable of keeping up the march pace, have lower morale as they have not yet been indoctrinated into the glories of the regiment, etc.
These aren't rules specific and I imagine they could easily be worked into whatever your preferred rule set is.