spawn multiple robots in RVIZ using one URDF/XACRO file

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I want to spawn swarm of robots in RVIZ from one URDF under different namespaces and individually control them. Currently I have transforms for different robots and joints states under unique namespaces. I also run robot_description under different namespaces, but the content of URDF like its joints and links are not resolved under the namespaces. For example in RVIZ robot model is looking for right_wheel to base_link transform which actually do not exist, but the transform for right_wheel to robot_01/base_link exists. Can anyone link or guide for a cleaner way than the one here

Currently I am having multiple yaml files which are loaded under different namespaces using rosparam.uploadparams(). But it does not work for XML files.