I'd Sensors/Actuators in the same plugin so we can resolve motor encoder ports from the V5ActuatorCommand msg
Most general approach is to supply a matrix that maps from motor/encoders to gazebo joints. That way we can easily tweak ratios or add fancy mechanisms (differential, specifically lol) using the same interface.
Our simulation package should be migrated to interface directly with V5ActuatorCommand.msg and V5SensorUpdate.msg ROS topics.
This allows nodes in ghost_ros to be agnostic to the platform (hardware vs simulator)