Setting up My Passport Wireless Pro with existing My Cloud App

I have just purchased a new 3TB My Passport Wireless Pro [for photographic use] and have an existing My Cloud 2TB Cloud storage unit connected to my home network - which I access from my iPhone/iPad/ Apps and Mac etc.
Is it best to operate these two devices separately via two different My Cloud Apps on my portable devices - and is it possible to actually operate this way?

No, if you have more than one device controlled by app, you will see them listed in the app, so select the one you need. If you do not have the complete user manual to refer to, download it from the WD support site. You NEED the user manual!