Use Deviator to persuade your opponents to turn over to the other side
(Ordos's side), then. Click on the attackbutton and attack something
towards the enemy buildings. Click on the attackbutton again and wait
for the vehicle to change to his natural colour. Attack an enemy vehicle
or a building. The opponents won't bother and the vehicle can shoot the
enemy (or his friends).
Thanks to Mikael lmestig for this helpful cheat.
To destroy or weaken (so you can capture it) a Rocket Turret, use rocket launchers or the Sonic Wave Tank (my favorite). Than let it attack the ground just in front of the Rocket Turret. If you are at the right angle, you do manage to hit the Rocket Turret and it won't attack you! You have to experiment a bit with it, as it isn't 100% proof. Sometimes you do get attacked by the Rocket Turret, or your opponent sends in some tanks, so keep looking!
Sonic Wave Tanks can be very usefull for defense, but NOT close to your own camp. Try to find a bit rock that is near a path of your opponent. Position one or more Sonic Wave Tanks and leave them in guard mode. Enemy vehicles will drive past your Sonic Wave Tanks, even if the tanks start attacking (but STILL in guard mode). That way your enemies are weakened and your own Rocket Turrets can finish them more easily.
If you have a Carry-all, make sure your Repair Facility is surrounded by other buildings or vehicles. That way repaired vehicles can't leave the Reapir Facility and the Carry-all will put it back where it came from. Otherwise repaired vehicles will drive just outside the Reapir Facility.
Thanks to Ji Yong Dijkhuis for this useful tip.