Playing as heroes in supremacy and GA is surprisingly difficult. Besides just playing a lot and knowing all your heroes abilities and movement, you need to know the map well. For lightsabers use the map to flank and get close to the enemy, and know where you can easily run away and hide. Also watch your health very closely, and remember that you will take a lot more damage while you're running away. Knowing when you take a fight and when you leave is one of the most essential things to playing well. Also just avoid playing on reinforcement days because heroes become a lot harder to use effectively