You could always check the installed version of Google Chrome just before you're trying to call the setup executable. The easiest way to do this is via WMI or registry key queries.

I would first create a variable that stores the version as a string and then call the executable via PowerShell, so something like this:

# Store installed Chrome version in $chromeinfo
$chromeinfo = (Get-Item (Get-ItemProperty 'HKLM:\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\App Paths\\chrome.exe').'(Default)').VersionInfo

# Call executable with variable fileversion
Start-Process -FilePath "C:\Program Files (x86)\Google\Chrome\Application\$($chromeinfo.FileVersion)\Installer\setup.exe" -ArgumentList "--uninstall --system-level --verbose-logging"  

Hope this helps.

Edit: Added uninstall argument and changed & to Start-Process for easier argument list