If I set the AlbumSort tags on the three to "The Hits 1", "The Hits 2", and "The Hits 3" then both the Column Browser and Album View display them in the wrong order ("The Hits 2", "The Hits 3", "The Hits"). I then went to the Album mapping table in Sorting Preferences and noticed that when I changed the AlbumSort tags for "The Hits 2" and "The Hits 3", the tags changed (i.e., they changed from the grayed-out "Hits 2, The"/"Hits 3, The" to normal text "The Hits 2" and "The Hits 3"), but no entries were created in the mapping table.
I then created mappings manually, and the Column Browser and View both sorted them correctly.
But I shouldn't need to create mappings, or change tags, for 2 and 3. I just need a tag/mapping for 1 because the 1 is missing from the title. Somehow the mapping isn't being treated as it if was a tag.