Yes, you can control your army during the attack! There is a special perk Pointfinder. If you want attack a certain building, push this button (you can find it at the buttom on the right side on your screen) and then tap the building, that you choose to attack. But remember - this perk works only a few seconds and need some time to recover, so choose carefully! In other ways troops will start acting entirely autonomously after landing on the battlefield. Each combat unit has its own priority target. Take advantage of this feature to maximize the effectiveness of your attack!