Each simconnect is a different version and will not overlap on the other, where should an addon/program need a particular version it should find what it needs from the list of installed simconnects.
You'll end up with them showing in "Programs and Features" like the below pic where I've performed a search in the RH upper search field to list just the simconnects.
Simconnect msi installers can be found in the path below,
~\Prepar3D v5\redist\Interface\
where ~\ indicates the path you've chosen to install P3D (v5 in the path snippet).
e.g. for mine it's "H:\Lockheed Martin\Prepar3D v5\redist\Interface\"
