Need help in loading 3 Rviz applications for 3 turtlebots in simulation

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Hi, I am currently looking at this fleet manager that utilizes both ROS and ROS2. I hoping to get help with displaying the 3 turtlebots in an RVIZ simulation, be it all in one RVIZ app or 3 separate RVIZ applications.

The following are the content of the launch files used:

multi_turtlebot3_ff.launch <launch> <arg name="model" default="$(env TURTLEBOT3_MODEL)" doc="model type [burger, waffle, waffle_pi]"/> <arg name="set_map_frame" default="map"/>

  <!-- launches the basic multi turtlebot3 world -->
  <include file="$(find turtlebot3_gazebo)/launch/multi_turtlebot3.launch">
    <arg name="model" value="$(arg model)"/>
  </include>

  <!-- Map server -->
  <node pkg="map_server" name="map_server" type="map_server" 
      args="$(find free_fleet_examples_ros1)/test_maps/house.yaml">
    <param name="frame_id" value="$(arg set_map_frame)"/>
  </node>

  <!-- launch the navigation stacks of 3 turtlebot3s-->
  <arg name="tb3_0_prefix" value="tb3_0"/>
  <group ns="$(arg tb3_0_prefix)">
    <include file="$(find free_fleet_examples_ros1)/launch/single_turtlebot3_ff.launch">
      <arg name="set_base_frame" value="$(arg tb3_0_prefix)/base_footprint"/>
      <arg name="set_odom_frame" value="$(arg tb3_0_prefix)/odom"/>
      <arg name="set_map_frame" value="$(arg set_map_frame)"/>
      <arg name="open_rviz" value="true"/>
      <arg name="initial_pose_x" default="-6.58309602737"/>
      <arg name="initial_pose_y" default="-0.598859667778"/>
      <arg name="initial_pose_a" default="1.57"/>
    </include>
  </group>

  <arg name="tb3_1_prefix" value="tb3_1"/>
  <group ns="$(arg tb3_1_prefix)">
    <include file="$(find free_fleet_examples_ros1)/launch/single_turtlebot3_ff.launch">
      <arg name="set_base_frame" value="$(arg tb3_1_prefix)/base_footprint"/>
      <arg name="set_odom_frame" value="$(arg tb3_1_prefix)/odom"/>
      <arg name="set_map_frame" value="$(arg set_map_frame)"/>
      <arg name="open_rviz" value="true"/>
      <arg name="initial_pose_x" default="6.72441768646"/>
      <arg name="initial_pose_y" default="-1.08069348335"/>
      <arg name="initial_pose_a" default="1.57"/>
    </include>
  </group>

  <arg name="tb3_2_prefix" value="tb3_2"/>
  <group ns="$(arg tb3_2_prefix)">
    <include file="$(find free_fleet_examples_ros1)/launch/single_turtlebot3_ff.launch">
      <arg name="set_base_frame" value="$(arg tb3_2_prefix)/base_footprint"/>
      <arg name="set_odom_frame" value="$(arg tb3_2_prefix)/odom"/>
      <arg name="set_map_frame" value="$(arg set_map_frame)"/>
      <arg name="open_rviz" value="true"/>
      <arg name="initial_pose_x" default="0.30019775033"/>
      <arg name="initial_pose_y" default="2.9819111824"/>
      <arg name="initial_pose_a" default="0.0"/>
    </include>
  </group>

  <!-- launch the free fleet clients of 3 turtlebot3s-->
  <node name="$(arg tb3_0_prefix)_free_fleet_client_node" 
      pkg="free_fleet_client_ros1"
      type="free_fleet_client_ros1" output="screen">
    <param name="fleet_name" type="string" value="turtlebot3"/>
    <param name="robot_name" type="string" value="$(arg tb3_0_prefix)"/>
    <param name="dds_domain" type="int" value="42"/>
    <param name="max_dist_to_first_waypoint" type="double" value="10.0"/>
    <param name="battery_state_topic" value="$(arg tb3_0_prefix)/battery_state"/>
    <param name="robot_frame" value="$(arg tb3_0_prefix)/base_footprint"/>
    <param name="move_base_server_name" value="$(arg tb3_0_prefix)/move_base"/>
  </node>

  <node name="$(arg tb3_1_prefix)_free_fleet_client_node" 
      pkg="free_fleet_client_ros1"
      type="free_fleet_client_ros1" output="screen">
    <param name="fleet_name" type="string" value="turtlebot3"/>
    <param name="robot_name" type="string" value="$(arg tb3_1_prefix)"/>
    <param name="dds_domain" type="int" value="42"/>
    <param name="max_dist_to_first_waypoint" type="double" value="10.0"/>
    <param name="battery_state_topic" value="$(arg tb3_1_prefix)/battery_state"/>
    <param name="robot_frame" value="$(arg tb3_1_prefix)/base_footprint"/>
    <param name="move_base_server_name" value="$(arg ...