There is no 'official lore', neither any mandatory lexicons, paint schemes nor stats cards. Other expensive, scale insensitive, bloated manufacturers are out there for those things. ;)
Those 'new abductees' either get dropped into a Death Fields scenario with the weaponry and tactics they came with (and get slaughtered by a single Grognard heavy plasma cannon) or end up in a 22nd century boot camp and upgraded with C22 kit to go out to play.
I'm using the XR ruleset which does allow for the fielding of primitive troops possibly upgrading to primitive weapons/armour.
An Oh Rah! troop can be presented with 100's of genuine Grand Armee, Imperial Garde and Cuirassiers to shoot up and feel arrogant about.
- La Garde (15 figs)- Primitive Inf , Fanatic, Primitive Missle, Mob = 5pts
- Cuirassier (10 Figs)- Primitive Inf, Mobile, Armoured, Fanatic, Large Unit = 5pts
- Ligne (15 figs) - Primitive Inf, Primitive Missile, Young Warrior, Mob = 3 pts
- Chasseur (10 figs ) - Primitive Inf, Mobile, Young Warrior, Large Unit = 2pts
6*15 French line + 3 *10 Chasseur -> 24 pts
- Oh Rah! Squad - HI, Large, AP, MG = 7pts
- Oh Rah! Recon - Recon, Sniper, Veteran = 6pts
- OhRah! Weapons Team - Support, Artillery, Indirect = 8pts
- OhRah! Humvee - Soft veh, Technical, Green = 3pts
An Oh Rah! detatchment of one of each -> 24pts
That is, in therory, a balanced 4'x4' table scenario - can that French Divisional Force survive an encounter scenario?