Of course not everything has to roll along the ground. As mentioned, drones will stay in the skies, and you will also have a number of other aerial clones at your disposal. Arrow Barrages and other multi-hit aerial strikes are good for taking out approaching foes, and the long range moves can be aimed straight at the enemy tower. These are best used for defensive measures, or when you have just a few more hit points to go on the enemy health bar.