Yup, these games were also released in 93 and around the Working Designs first started doing their deluxe packaging that eventually gained them so much fame. The foil stamping in these packages made it's way into the Lunar releases for SegaCD and became a trademark for a lot of their games on Sega Systems.
My best guess is that he liked the way spinecards looked and took the natural progression to make a sleeve that covered most of the package, or maybe the concept was from sleeves that go around VHS tapes. I have no clue why they didn't just take the extra step to make it a cardboard ring that went completely around the game. Those cardboard rings are now pretty much standard on any "special" DVD or Blu-ray release.