There aren't 5 copies of the Addon Manager installed, there's just one, you have 5 copies of its *uninstaller* instead, which might be due to the fact that you might have manually removed the files sometimes, which will confuses the Windows Control Panel.
But in any case, it won't make any difference whether you have 5 or 1 entries there, the installed copy is only one, since there's only one place the files go (the FSX folder) and each time you install the Addon Manager, it will just overwrite the same files over and over, possibly with new version, but there will never be "multiple copies" at any time.
So, you can launch the uninstallers or not, it won't make any difference, other than your peace of mind of not seeing multiple entires on the Add/Remove programs page.
Of course, in case you decide to launch all uninstallers to get rid of the multiple entries, you'll have to reinstall it once, since each time you launch one of the 5 uninstallers, it will remove the same copy of the same files so, even if you left one entry, there will be no Addon Mananager left. So, launch all uninstallers so you don't have any Addon Manager entry, and reinstall the Stand-Alone Addon Manager once.
As I've said, all of this is not required at all if everything's working, it's just cosmetic.
