Thanks for the tips, gents.
I did a variation on this that ended oddly.
Armed myself as the saboteur, as mentioned above, from the briefing
screen. Had the 2 snipers hold fire, and laid 3 satchels in the road intersection
in the ville to the east.
Had them come down and open up from the SE and SW corners. I was at
the main gate picking off any runners. Only had 2, and the snipers did
in the rest quite handily. No truck left, but one did move a bit.
Sent them into the camp, and I drove the trucks out singly, and parked them
over the satchels. Detonated, and got objective to hit the chopper.
The Blackhawk hovered over the spot, but all I got was a re-arm icon.
As I ran around the back to try the other side, it boogied off without me.
Just out of the flat, it stayed low, and augered right into a tree and
burst into flame!
I got objective completed, but what a way to end it!