Block the enemies, while damaging them

First get either a mage in the upper left and a denas bastion in the upper middle, place the soldiers in the chockepoint in the middle and then place the elephant in the middle spot that's a little to the left and place it in the chokepoint, then place the sandworm in the middle spot that's a little to the right and more mages and bastions in random spots, focus on upgrading the sandworm and mages and stun enemies with the elephant in the chokepoint. That's all. 😊