Multiple Drone spawn by sdf: cannot arm or change mode

I am trying to follow the instruction from the last section (Multiple Vehicles using SDF Models) of:

Multi-Vehicle Simulation with Gazebo | PX4 User Guide

I modified single_vehicle_spawn_sdf.launch so it will spawn my sdf model - iris_stereo_camera.
All three drones are able to spawn successfully, but when I try to arm all of them by using:

rosservice call /uav0/mavros/cmd/arming True
rosservice call /uav1/mavros/cmd/arming True
rosservice call /uav2/mavros/cmd/arming True

Only uav0 were able to arm. The other two returns false to the service. This is strange because I can see all three services when tying rosservice list.

This is my single_vehicle_spawn_sdf.launch:

  <?xml version="1.0"?>
<launch>
    <!-- Posix SITL environment launch script -->
    <!-- launchs PX4 SITL and spawns vehicle -->
    <!-- vehicle pose -->
    <arg name="x" default="0"/>
    <arg name="y" default="0"/>
    <arg name="z" default="0"/>
    <arg name="R" default="0"/>
    <arg name="P" default="0"/>
    <arg name="Y" default="0"/>
    <arg name="drone_ns" default=""/>
    <!-- vehcile model and config -->
    <arg name="est" default="ekf2"/>
    <!-- <arg name="vehicle" default="iris_stereo_camera"/> -->
    <arg name="vehicle" default="iris"/>
    <arg name="model" default="iris_stereo_camera"/>
    <arg name="ID" default="1"/>
    <env name="PX4_SIM_MODEL" value="$(arg vehicle)" />
    <env name="PX4_ESTIMATOR" value="$(arg est)" />
    <arg name="mavlink_udp_port" default="14560"/>
    <arg name="mavlink_tcp_port" default="4560"/>
    <!-- PX4 configs -->
    <arg name="interactive" default="true"/>
    <!-- generate sdf vehicle model -->
    <arg name="cmd" default="xmlstarlet ed -d '//plugin[@name=&quot;mavlink_interface&quot;]/mavlink_tcp_port' -s '//plugin[@name=&quot;mavlink_interface&quot;]' -t elem -n mavlink_tcp_port -v $(arg mavlink_tcp_port) $(find px4)/Tools/sitl_gazebo/models/$(arg model)/$(arg model).sdf"/>
    <param command="$(arg cmd)" name="model_description"/>
    <!-- PX4 SITL -->
    <arg unless="$(arg interactive)" name="px4_command_arg1" value=""/>
    <arg     if="$(arg interactive)" name="px4_command_arg1" value="-d"/>
    <node name="sitl_$(arg ID)" pkg="px4" type="px4" output="screen" args="$(find px4)/build/px4_sitl_default/etc -s etc/init.d-posix/rcS -i $(arg ID) -w sitl_$(arg vehicle)_$(arg ID) $(arg px4_command_arg1)">
    </node>
    <!-- spawn vehicle -->
    <node name="$(arg vehicle)_$(arg ID)_spawn" output="screen" pkg="gazebo_ros" type="spawn_model" args="-sdf -param model_description -model $(arg vehicle)_$(arg ID) -x $(arg x) -y $(arg y) -z $(arg z) -R $(arg R) -P $(arg P) -Y $(arg Y)"/>
</launch>

And this is my multi_uav_mavros_sitl_sdf.launch, I have not modify anything in this launch file
> <?xml version="1.0"?>

<launch>
    <!-- MAVROS posix SITL environment launch script -->
    <!-- launches Gazebo environment and 2x: MAVROS, PX4 SITL, and spawns vehicle -->
    <!-- vehicle model and world -->
    <arg name="est" default="ekf2"/>
    <arg name="vehicle" default="iris"/>
    <arg name="world" default="$(find mavlink_sitl_gazebo)/worlds/empty.world"/>
    <!-- gazebo configs -->
    <arg name="gui" default="true"/>
    <arg name="debug" default="false"/>
    <arg name="verbose" default="false"/>
    <arg name="paused" default="false"/>
    <!-- Gazebo sim -->
    <include file="$(find gazebo_ros)/launch/empty_world.launch">
        <arg name="gui" value="$(arg gui)"/>
        <arg name="world_name" value="$(arg world)"/>
        <arg name="debug" value="$(arg debug)"/>
        <arg name="verbose" value="$(arg verbose)"/>
        <arg name="paused" value="$(arg paused)"/>
    </include>
    <!-- UAV0 -->
    <group ns="uav0">
        <!-- MAVROS and vehicle configs -->
        <arg name="ID" value="0"/>
        <arg name="fcu_url" default="udp://:14540@localhost:14580"/>
        <!-- PX4 SITL and vehicle spawn -->
        <include file="$(find px4)/launch/single_vehicle_spawn_sdf.launch">
            <arg name="x" value="0"/>
            <arg name="y" value="0"/>
            <arg name="z" value="0"/>
            <arg name="R" value="0"/>
            <arg name="P" value="0"/>
            <arg name="Y" value="0"/>
            <arg name="vehicle" value="$(arg vehicle)"/>
            <arg name="mavlink_udp_port" value="14560"/>
            <arg name="mavlink_tcp_port" value="4560"/>
            <arg name="ID" value="$(arg ID)"/>
        </include>
        <!-- MAVROS -->
        <include file="$(find mavros)/launch/px4.launch">
            <arg name="fcu_url" value="$(arg fcu_url)"/>
            <arg name="gcs_url" value=""/>
            <arg name="tgt_system" value="$(eval 1 + arg('ID'))"/>
            <arg name="tgt_component" value="1"/>
        </include>
    </group>
    <!-- UAV1 -->
    <group ns="uav1">
        <!-- MAVROS and vehicle configs -->
        <arg name="ID" value="1"/>
        <arg name="fcu_url" default="udp://:14541@localhost:14581"/>
        <!-- PX4 SITL and vehicle spawn -->
        <include file="$(find px4)/launch/single_vehicle_spawn_sdf.launch">
            <arg name="x" value="0"/>
            <arg name="y" value="4"/>
            <arg name="z" value="0"/>
            <arg name="R" value="0"/>
            <arg name="P" value="0"/>
            <arg name="Y" value="0"/>
            <arg name="vehicle" value="$(arg vehicle)"/>
            <arg name="mavlink_udp_port" value="14561"/>
            <arg name="mavlink_tcp_port" value="4561"/>
            <arg name="ID" value="$(arg ID)"/>
        </include>
        <!-- MAVROS -->
        <include file="$(find mavros)/launch/px4.launch">
            <arg name="fcu_url" value="$(arg fcu_url)"/>
            <arg name="gcs_url" value=""/>
            <arg name="tgt_system" value="$(eval 1 + arg('ID'))"/>
            <arg name="tgt_component" value="1"/>
        </include>
    </group>
    <!-- UAV2 -->
    <group ns="uav2">
        <!-- MAVROS and vehicle configs -->
        <arg name="ID" value="2"/>
        <arg name="fcu_url" default="udp://:14542@localhost:14582"/>
        <!-- PX4 SITL and vehicle spawn -->
        <include file="$(find px4)/launch/single_vehicle_spawn_sdf.launch">
            <arg name="x" value="0"/>
            <arg name="y" value="-4"/>
            <arg name="z" value="0"/>
            <arg name="R" value="0"/>
            <arg name="P" value="0"/>
            <arg name="Y" value="0"/>
            <arg name="vehicle" value="$(arg vehicle)"/>
            <arg name="mavlink_udp_port" value="14562"/>
            <arg name="mavlink_tcp_port" value="4562"/>
            <arg name="ID" value="$(arg ID)"/>
        </include>
        <!-- MAVROS -->
        <include file="$(find mavros)/launch/px4.launch">
            <arg name="fcu_url" value="$(arg fcu_url)"/>
            <arg name="gcs_url" value=""/>
            <arg name="tgt_system" value="$(eval 1 + arg('ID'))"/>
            <arg name="tgt_component" value="1"/>
        </include>
    </group>
</launch>
<!-- to add more UAVs (up to 10):
Increase the id
Change the name space
Set the FCU to default="udp://:14540+id@localhost:14550+id"
Set the malink_udp_port to 14560+id) -->

Are there any additional changes I need to make in order to successfully arm all three drones?

Also, if I change the model arg in signle_vehicle_spawn_sdf.launch back to iris instead of iris_stereo_camera, I was able to arm all three drones.