Tried. It doesn't work
Here is what I've tried so far -
1st time, I tried moving to the trucks, and using them as cover, then shooting. It fails because the aliens will ambush you from above, one shot one kill most of the times.
After seeing that tactic fail, I moved with 4 soldiers to the small canyon where there is a small shelter, to wait for the aliens to regroup and clear the high slopes. This failed too when most of the aliens remained near the trucks and when I tried to get some good positions they sniped me, because have more range with their weapons.
After that I reloaded the game, and requiped some of my squad with grenade launchers (HIT). This works better, after the aliens regroup near the trucks, I could bomb them with grenades from a slope. This fails too because the aliens have much more range and can shoot through slopes sometimes. Anyway, they can hit (kill) from very very far, which is pretty annoying. After I showered them with grenades from the launcher, I killed about 2-3 then both of my "grenadiers" got killed from very far, no matter how I tried to hide.
I kept a group in the aircraft, but that got sniped from above too, and they were quite useless to humanity anyway, because they couldn't hit any alien from that distance.
So after trying the described tactics many times, and a mix of them, I gave up quite irritated.
I'm not new to such games, actually I have played alot of X-COM, JA2, Fallout (including tactics) and so on... but I haven't seen this kind of map anywhere.