My guild had this same issue last night. We weren't prepared for the it the first time and wiped after he called about 8 trooper clones. The second time we were ready and took off running as soon as he called the third clone. By the time we ran far enough for the boss to reset we had gotten the trooper clone billboard message 18 times. There was a train of red dots following us through the instance until they finally reset around where the droid trio boss fight happens.