The way I did the level was to first capture the AV turrets and the command centre, then have command points flowing in. Onced it reached 5000, I then destroyed the 4 imperial communication towers. That then moves the game to the next stage of the level, in which you can order down reinforcements and fight the imperial offensive attack.
You may not be getting command points because of the force you start the level with. I basically had troopers + infiltators + repair droid + medical droid + two Loratus mobile proton-torpedo launchers.