Hi a few questions about following an object

[zj0042]

Hi all,
I am trying to let uav2 follow uav1. Due to the programming language (python and C++), I can't replace tracker + controller on MRS with mine. But I figure out some solutions. Could anybody please review it and give some comments? I hope to find the most possible and fast solutions for this scenario. Uav1: flies along a trajectory that is loaded by trajectory_loader, then start_trajectory_tracking. normal config，for example: MpcTracker + MpcController. and has constraints and gains.
Uav2: is expected to follow uav1 and have uav1 in its camera images.
Solutions:

1. uav2: set uav2 with NullTrakcer + MpcController. Set collision, gain, and constraint is disabled. uav1：normal config，for example: MpcTracker + MpcController. (get the uav1's GPS location, then do it to uav2: setreference() . this is the simplest way. Of course, here some simple ideas like PID can also be used. )
2. uav2: set uav2 with SpeedTrakcer + MpcController: set collision, gain, and constrain is disabled. Calculate the desired position (e.g., the current uav1's position) and then calculate the speed and acc, height and heading, and publish to the topic /control_manager/speed_trakcer/command. Does this mean the trakcer will transfer will do nothing and controller will transfer this speed to an attitude command to hixhawk? (mavros/setpoint_raw/attitude)
3. are the topics /control_manager/attitude_cmd and /mavros/setpoint_raw/attitude same?