Yes the Change Auditor Win32 client may be installed on multiple workstations. The steps to install the Client are the same for a workstation as for the Coordinator server.
The installation of the Client can be run from a network share following the same steps as for the default installation or you can copy the Client .msi from the downloaded installation media folder 'CA6xxxxxx_XXXX\Installation\x64\Quest Change Auditor Client 6 (x64).msi' to the workstation. Then open a command prompt as an administrator, browse to the Quest Change Auditor Client 6 (x64).msi and run the install.
Please note the Change Auditor Web Client is available as an alternative to the Change Auditor Win32 fat client. The Web Client provides all of the same functionality except for the ability to deploy agents.
Please review the Knowledge Article 147195 for instructions and video on 'How to install the Change Auditor Web Client'
Please note: If you have a Change Auditor version prior to 6.9.5, any folder/registry paths referenced may contain a non-Quest branded path.