Some thoughts on how an insurgent faction could be implemented:

Since they don't have helis, focus on high mobility, artillery and ground control.

. No commander UAV
. Power plants only required for base defenses.
. No Research Center (cost shifted to higher tier production structures)
. Instead of Oil Dericks, there are 2 less efficient income structures available from the start, that produce either construction or ammo (Construction Yard and Black Market).
. Lower profile structures (making their base end up looking more like an Al-Basrah suburb).
Possibly remove Ultra walls or replace them with a wall about half that height.

. 3 vehicle production structures:
Garage: (Cheap, available after barracks)
Produces simple technicals (transport, logi, dshk, spg) and logi trucks. Cheap vehicles that can be spammed.

Chop shop: (Medium cost, available after Garage)
Produce heavily armed technicals (AA, mortar, bmp cannon, rocket arti) and up-armored technicals including dshk humvees.

Arms Dealer: (Expensive, available after chop shop)
Produces armored vehicles, everything from BRDM to BMP1 and T62, including more expensive MEA rocket variants.

. Ammo Caches: New fob structure that generates ammo on it's parent fob at the rate of a derrick (limited to 1 per fob).

So basically they can operate without power, but their base expands with lots of less efficient income structures.

Their early game depends on using fragile unarmored vehicles and infantry to counter conventional light armor.

They have no air power but can counter with numerous air defense fob emplacements and the ability to generate ammo to become independent of supply depots.

Their heavy armor arrives a little later and is inferior, but can be mass produced more easily alongside light vehicles to support it.

They can destroy the enemy base from range with rocket arti or hell cannons.

To defeat insurgents you must dominate with air power or superior vehicles and your infantry must clear out their fob emplacements that pose a threat to the base, and air assets.