This is a fairly minor suggestion, but is meant to help make the elite bots in cooperative even more challenging than they currently are.

Current
As it stands, the elite bots receive some nicer weapons such as the AMRs, extra grenades, and higher point cost rifles and such. In actual gameplay, this usually means jack-shit due to the TTK being incredibly low. Good rifle or bad, a well-placed shot from a bot usually kills in one hit. Only the AMR bots have a significant effect due to increased wall penetration and their ability to near-instantly down aircraft.

Visually, the elite bots stand out like a sore thumb compared against the regular bots, especially on the insurgent side. For insurgents they typically wear full blackout attire, while security typically use slimfit outfits, high cut helmets, combat classes, and more modern camo options like polycam. Ordinarily, I'd say that this lets you know who to shoot immediately at first glance.

Suggestion
The suggestion is to screw with a player's first glance. The idea is to screw with the silhouette and color palette of the elites by introducing "Contractors" for security and "Militants" for insurgents.

Militants and Contractors would spawn with clothing items (and possible camo patterns) from the enemy team's faction in an attempt to mix-up players and make them hesitate before firing. That being said, each side will have things from their faction that don't change, such as the nature of their head-wear, armor, and rigs/backpacks so that someone perceptive can still identify an enemy.

Clothing Pool for Elites
This area will go over clothing combinations (usually at least 1-2 items from the enemy faction)

Contractors
Headwear: Baseball, Too Cool, Watch Cap, High Cut Variants
Facewear: Gaiter or Balaclava Variants, Nothing
Eyewear: Combat Glasses, Shades [INS], Aviators [INS]
Gloves: Usual SEC options
Tops: Softshell Jacket Solid, T-shirt Plain [INS], Polo Plain [INS], Button-up Flannel / Plain variants [INS],
Bottoms: Jeans [INS], Cargo Pants [INS]
Shoes: Standard Issue, Lightweight
Camo: (For gear) Solid Color, Polypat, usual Elite camo options currently used.

Overall the general aesthetic is a plainclothes operative. They're probably in-field to act as advisors for the local security force, or were tasked with protecting assets in the area, and have finally gotten involved with the fighting as it got closer to their position.

Militants
Facewear: Back-Knot Variants, Ninja Variants, Balaclava Variants (including skull patterns)
Eyewear: Combat Glasses [SEC], Shades, Aviators
Gloves: Usual INS Options
Tops: Blouse [SEC], Camo Hoodie / T-shirt (using actual camo), All T-shirt variants, Plain Hoodie, All Button-up variants, All Polo variants
Bottoms: Trousers [SEC], Cargo
Shoes: Standard Issue, Sneakers, Comfort
Camo: Older camouflage styles, or styles used by regional security. (Desert Rocks, Digital Forest, DCU, DBDU, DPM, M81, Tigerstripe)

The general aesthetic are veteran fighters with experience in extremist organizations, or who were formerly members the nation's security and police forces. They probably act as trainers and field commanders, but are finally forced to fight either because their subordinates can't cut it, or the frontline has gotten too close.

Conclusion
In summation, this suggestion is intended to make target identification moderately more difficult in coop modes. A moment of hesitation can lead to a player's death. Insurgency is a game where the victor is usually determined by who shoots first thanks to the hyper-lethality of the gameplay. Messing with silhouettes and colors ups the challenge without resorting to tampering with bot parameters, and will always make sure that when a player dies to an elite enemy, the outcome is entirely on their slow target identification instead of a slightly higher chance of being John Wicked.