I feel like a helpless toddler, between unconscious incompetence to conscious...

I've tried snapping together the two null objects, odd results. But first, I had the idea to scale my null objects large enough to see them better when viewing the full mesh, this in anticipation of rotating one mesh (via its parent null) against the other. I also shaded one set of three null objects a different color from the other, making registration yet easier. Acquiring such simple skills ate a little time. Then I go to play with the snap alignment tool, and encounter totally unexpected behavior. Again, three null objects (spheres) precisely located at common points of interest on mesh 1, the mesh and the latter two null objects each parented to the first null — I move null 1, the other two nulls and mesh 1 follow. I do the same for mesh 2 and its corresponding 3 nulls. In the Hypergraph panel I select null 1, shift select null 2, I go to Modify, Snap Align Objects, Align Objects, see movement, but parent null 1 and parent null 4 aren't in the same location. If I move parent null 1 closer to null 4 before the snap align, I get different results, so it appears there's some kind of averaging of locations between the parent and all leaf objects that's operating on the alignment. Any ideas? Thanks again, it's kind of embarrassing being a toddler drooling uncontrollably;^(