How to prevent ROS namespace from overwriting topic names?

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I am now working on the simulation with multiple robots and I want to use namespaces to organize the nodes better. However, I am also trying some information exchange among robots so they are also subscribing to topics from others' namespaces.

Here is the part in my launch file I start the node send_follow_waypoints

<node pkg="uuv_control_utils" type="send_follow_waypoints.py" name="$(anon name)">
    <param name="uuv_name" value="$(arg uuv_name)" />
    <param name="follow_name" value="$(arg follow_name)" />
    <param name="max_forward_speed" value="$(arg max_forward_speed)" />
    <param name="heading_offset" value="$(arg heading_offset)" />
    <param name="use_fixed_heading" value="$(arg use_fixed_heading)" />
    <param name="radius_of_acceptance" value="$(arg radius_of_acceptance)" />
    <param name="start_time" value="$(arg start_time)" />
    <param name="x_shift" value="$(arg x_shift)" />
    <param name="y_shift" value="$(arg y_shift)" />
    <param name="z_shift" value="$(arg z_shift)" />
    <param name="success_rate" value="$(arg success_rate)" />
</node>

And here is my subscriber inside send_follow_waypoints.py:

rospy.Subscriber('/%s/pose_gt' % follow_name,
            Odometry,
            follow_pose_callback)

I want the robot with uuv_name to subscribe to the topic /follow_name/pose_gt, but if I add an ns="$(arg uuv_name)" tag to the node, it would try to subscribe to /uuv_name/follow_name/pose_gt. Is there some way to stop the namespaces from changing the topic names?