I have been using the instructions in http://docs.erlerobotics.com/simulation/configuring_your_environment to simulate one Erle-Copter and test some control algorithms. Now I want to simulate a group (maybe 3 or 4) of drones. I am able to run multiple instances of the Pixhawk SITL simulator, however, for what I understood, the ardupilot_sitl_gazebo_plugin was made with just one drone in mind, so it connects to just one SITL. Is there anything I can do to run multiple Erle-Copters in Gazebo? Thank you!