Weaponry
I think that the Separatists would have 3 groups of weapons that they can choose from, it can be from 1 group or a mixture of all 3.
1: U.S/British Supplied Weapons
The Enemy of my Enemy is my Friend.
Since the U.S./British is also fighting the M.E.C. and have been known in the past to supply it's enemies' enemies with weapons, so the Separatists could have M16A1's, Stingers, M67 Hand Grenades(possibly), FN FALs(I know it's a WIP), and other weaponry like C4 and the U.S. AT mines.
2: Captured M.E.C. Weapons
Kind of self explanatory, an organized resistance fighting a better supplied enemy that occupies the same territory might be inclined to use there enemies weapons because of more available ammo. G3's are the first that come to mind they can use, plus RPG-26s and more average M.E.C. grunt weapons that may be used (MP5's captured from M.E.C. BDRM operators), no specialist weapons like Eryx or the M.E.C. sniper. Possibly the SA-7 Grail.
3: "Classical" Weapons
Ak-47s, RPG-7s, SVDs, Lee Enfield, RKG-3s, DShK's pretty much can fill the gaps.
Vehicles
Since this is a more evolved fighting force and not an insurgency they wouldn't use civilian hatchback cars. Technicals would be easily made or acquired, and captured URAL trucks or UAZ jeeps would also be common. Heavier captured weapons would most likely just be a BDRM-2 vehicle with the possibility of a Spandrel, and these would be more rare. No Tanks, APC's, or Aircraft .
Uniforms
I was thinking since this isn't an insurgency they would have a more uniformed outfits like the Militia, and also they wouldn't have to wear masks (they could if they wanted) because they control some land and don't live under the enemies nose. Old U.S. desert camo from the first Gulf War or some Woodland BDU's. Some M.E.C. style layouts for the more specialized kits since they'd probably take equipment from dead M.E.C. soldiers.
Map layouts
Though they are a more evolved fighting force they aren't strong enough to attack a well funded, better equipped enemy. The maps would most likely be in more remote areas of the Middle East preferably mountainous areas with caves that has a lot of cover from possible M.E.C. air support. There may be some maps where they have took over a populated area because the M.E.C. weren't in the area at the time. In all the maps I think it should be the M.E.C. doing the attacking because these Separatists are threatening to destabilize whatever area they are in, plus the Separatists wouldn't have the manpower/equipment to attack a more advanced opponent.
Game Modes
The remote area maps should be cache hunting, as if the M.E.C. were there to weaken the Separatists and to help prevent them from expanding. The populated maps would be AAS, as if the M.E.C. were there to liberate the people from the Separatists.
Please take this into consideration, besides from the what the Separatists would look like and a map has yet to be made or recycled, all the weapons/vehicles I mentioned are already in game, plus the Separatists would speak Arabic so no new voices are needed.
*Edit, WIP of the spreadsheet.
http://spreadsheets.google.com/ccc?key= ... PSGc&hl=en
