This was a great mission. It took me many tries and lots of patience to complete this one.
What I did was to establish a base by taking control of the nearby hq and power generator. I built a galaxite processor and VTS then wiped out the enemies directly to the north when they launched their big attack.
After their attack I was reasonably sure that there wouldn't be anymore attacks from that direction. If there are anymore remaining forces they will wipe out your base when you are away and it is game over
Next I built up my army with eagles and broadswords and made contact with the allies. Note that I didn't build a research center because it was too expensive with the limited galaxite.
I helped the allies attack the southern base and I had access to the galaxite field on the bottom left corner. The enemy patroled the bottom right area so I had to be patient to harvest galaxite and build up my army. After I had 6 broadswords and 6 eagles I attacked and destroyed the patrols and gained access to the bottom right galaxite field.
One hint is don't disturb any hornets nest if you don't have to. Some of the enemy forces won't attack unless you provoke them. Since the galaxite is limited you want to choose your battles wisely.
At this point you should be able to complete the mission. I won't reveal the surprise ending.
