I'd like to be able to make Obj03 which contains:
I know I can mix/match and place all three in a single hashtable, but I'm looking at having dozens of these custom objects "groups" and want to be able to pick and choose which Obj0x gets merged with Obj0y.
Yeah, there's not a "merge." That really goes against the original concepts of object-oriented programming, which is why; objects aren't simply "data structures," although in PowerShell we admittedly use them that way a lot. The most you could probably do is write a Merge-Object command which programmatically does this for you.