Alright so yes it is normal to have multiple vssadmin.exe (I'm not counting the vssadmin.exe.mui files) on your system. In fact, it's normal to have multiple copy of all your payload files (system files). Reason being that the WinSxS folder is what we call the "Component store". This is where Windows stores all the original copies of the system files and also every new update that you install, which contain payload files will be stored there as well. Windows will then copy the payload where it belongs (like in C:\Windows\system32) and link it to the copy in the Component store. This is why when you run SFC, corrupt files gets repaired (if the copy in the store is intact), and they don't get repaired (if the copy in the store is also corrupt). You should never touch any files in the WinSxS folder (or the Windows folder for that matter).
More explanations on the WinSxS folder can be found at the link below.https://support.microsoft.com/en-us/kb/2795190
If you want to "disable" vssadmin.exe, you should do it for the ones in System32 and Syswow64, not WinSxS.