Take over the Jungle Camp..

[JackintheBox]

bring heavy weapons............

Standalone&underslung launchers, RPG`s, LAW´s whatever you can get bring it!
Just blast into the rebel groups und shoot the stunned lads afterwards.
The downside to this though is that,
A: Heavy weapons rely more on your actuall skillpoints than any other weapons in the game. So you might fire some blasts into the sky/mountains/foilage if your mercs are not trained.
B: Judging the angle and range of heavy weapons will require some practice.
Most players find it very frustrating to use them(which they are) and will disregard them immediately.
But once you get the hang of it, they work very well in such scenarios.