This trophy may seem difficult at first but it is actually quite easy. It can be attempted in the Conquest mini-game found at all safe hubs in every zone. This can be obtained by playing either Na'vi or RDA.

The player must purchase and order troops to different locations to take control of different zones similiar to how your Assassin Army works in the Assassin's Creed games. Don't attempt this until you have completed the game because at the end you will have lots of credits to use.

The best way to do this is to only buy large amounts of soldiers (20,000-30,000) and send them out in one big wave taking on only zones with soldiers. You only need 50% of territories so you can take on the easy ones. Don't worry about building bases, just keep pushing on with your army of 20k-30k troops. With that size of an army you can still take on zones with Viperwolves or Banshees. One Viperwolf is worth roughly 200 soldiers and 1 banshee is about 500 soldiers.

If you make a mistake and end up losing too many zones, troops or credits just press the PS button on your controller and exit the game to XMB; progress is only saved if you exit out of the Conquest mode in game.