linux_guy, it sounds like we’re doing the same thing, i.e. I share your desire to use multiple mopidy instances for a multi-source, multi-sink sound system. As kingofsticks said, most mpd clients support dynamically selecting the outputs that the server it’s connected to uses at any given time. I’ve been using this for years with my system and it works, although the interface for changing outputs isn’t very graceful in most clients bc it’s not something MOST people use frequently so they don’t make it readily accessible.
Is there a reason you need to use mopidy instead of mpd? If you’re like most, the reason is that you want more sources than mpd supports (spotify! soundcloud!). For details on setting all this up, let’s put the details in the other thread I started: